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Pyrolysis of 29 coals with carbon contents of 71–92 mass% on a dry, ash-free basis (daf) has been performed mainly in a temperature-programmed mode at 10°C/min up to 800°C with a flow-type fixed bed quartz reactor, and some factors controlling HCl formation have been examined. The rate profiles of HCl formation exhibit at least three distinct peaks at around 260–360, 470–510 and 580–630°C, and the lowest temperature peak is present for 8 coals alone, whereas the middle and highest temperature peaks are common with almost all of the coals. The HCl profile is also affected by the size of coal particles and the height of coal particles in the fixed bed. Yields of HCl and char-Cl at 800°C for 28 coals except an American bituminous coal are 44–95 and 4–54%, respectively, and tar-Cl is as low as ≤ 7% in all cases. The chlorine distribution is almost independent of the heating rate in the range of 2.5–400°C/min and has no distinct relationship with carbon or chlorine content in coal, but HCl tends to increase with increasing amount of (Na + 2Ca) in coal with a corresponding decrease in char-Cl. When an Indonesian sub-bituminous coal is injected into an O2-blown entrained bed gasifier under pressure, there is an almost 1:1 relationship between carbon and nitrogen conversions, whereas the sulfur and chlorine are enriched in the remaining char, and the degree of the enrichment is higher with chlorine. The method of evaluating coal-Cl forms quantitatively using model chlorine compounds is proposed.

Catalytic decomposition of 2000 ppm NH 3 with an Australian limonite ore, which is composed mostly of goethite (α-FeOOH), has been studied from a viewpoint of hot gas cleanup with a vertical, cylindrical quartz reactor at 750–850 °C under a high space velocity of 45,000 h −1 . It has already been reported that the limonite achieves the almost complete decomposition of NH 3 in inert He at 500 °C and shows very stable performance in the reaction at 750 °C in the coexistence of 50–500 ppm H 2 S or at 850 °C in the presence of fuel gas components produced in an air-blown coal gasification process. In the coexistence of a high concentration of syngas (50% CO/25% H 2 ) produced with an O 2 -blown coal gasifier, the limonite is deactivated almost completely because of the remarkable occurrence of carbon deposition from the CO. On the other hand, the addition of small amounts of CO 2 and H 2 O, which are always included in actual coal-derived fuel gas, to the syngas improves the activity of the limonite, and conversions of NH 3 –N 2 at 750 and 850 °C become about 65% and almost 100% without carbon deposition, respectively. When several limonite-based catalysts with alkali metal and alkaline earth metal cations are prepared by the impregnation method and then used in the NH 3 decomposition at 750 °C in 50% CO/25% H 2 /5% CO 2 /3% H 2 O, fine particles of MgO derived from Mg cations can work more effectively as the promoter, and the 3 mass% Mg-added limonite maintains the high and stable NH 3 conversion of almost 100% for 25 h. In this case, no significant carbon deposition takes place. It is probable that MgO with strong basicity suppresses the carbon formation from CO, and that the limonite-based composite catalyst thus shows the superior performance in the decomposition of NH 3 in syngas-rich fuel gas that simulates product gas in O 2 -blown coal gasification.

Decomposition of pyrrole or pyridine with iron catalysts supported on carbons has been studied with a cylindrical quartz-made pulse reactor, into which liquid pyrrole or pyridine is injected as a pulse, in order to develop a novel hot gas cleanup method of removing the nitrogen present in tar as N 2 . The catalyst is mainly prepared by heating FeOOH precipitated onto powdery cellulose from FeCl 3 solution. Nanoscale iron catalysts with the average particle sizes of 25–30 nm can promote decomposition reactions of the N-containing heterocyclic compounds in inert gas at >500 °C and provide N 2 yields of 40–45% after the almost complete decomposition of pyrrole at 600 °C or pyridine at 650–700 °C. Iron catalyst with the mean size of 100–500 nm, prepared from Fe(NO 3 ) 3 impregnated with a commercial activated carbon, is also active for the decomposition of the heterocyclic N-compounds, but it is almost inactive for N 2 formation, the yields being as low as less than 2% in all cases. The increase in the number of pulses lowers the catalytic activity of iron nanoparticles for N 2 formation, whereas in situ H 2 treatment at 500 °C after reaction can restore it to the almost original state. On the basis of the above-mentioned results, it is likely that the activity of iron catalyst for N 2 formation from pyrrole or pyridine is very sensitive to the iron particle size, and the in situ H 2 treatment is effective for recovery of the decreased catalytic performance.

Polyacrylonitrile-derived activated carbon as a model of coal char has been heated in high-purity He at 10 °C/min up to 1000 °C with a flow-type fixed bed quartz reactor, and the catalysis of N 2 formation by precipitated iron has been investigated by use of XPS, TEM and XRD methods. Fine iron particles with the average size of 15 nm increase remarkably the formation rate between 600 and 1000 °C, and N 2 yield up to 1000 °C reaches about 65% at 1.9 mass% Fe. The XPS and XRD measurements after heat treatment exhibit that nitrogen functionality does not change significantly, but carbon crystallization occurs through the dissolution of iron nanoparticles into the carbon substrate. The in situ XRD analyses during heating reveal the formation of austenite that is solid solution of Fe and N (and/or C). Interestingly, the catalysis of N 2 formation by iron and the formation of austenite occur at almost the same temperature range of 600–1000 °C. It is thus likely that nanoscale iron particles move in the carbon matrix and react with heterocyclic nitrogen in order to produce the solid solution, which is subsequently decomposed into N 2 .

Two novel carbon-based Ni/Fe catalysts were developed and tested for catalytic decomposition of ammonia into N2 and H2. These catalysts were prepared using a mesoporous activated carbon (AC) support derived from a Canadian peat by H3PO4 activation. The newly developed catalysts proved to be highly active for ammonia decomposition. The conversion of 2000 ppm NH3 diluted in helium over the Fe catalyst reached as high as 90% at 750 °C and at the space velocity of 45,000 h−1, compared with only about 15% with the activated carbon alone without metal loading. The new catalyst of Fe/AC was also much more active than the Fe catalyst supported on a commercial activated carbon reported previously. In addition, the new Fe/Ni catalysts showed superior performance with respect to their resistance to catalyst deactivation. Both catalysts remained active as the reaction time increased up to 10 h without showing a sign of deactivation. Fresh and spent catalysts were characterized by XRD and XPS. A cycle mechanism, involving both metal phosphides and metal nitrides, was proposed for the NH3 decomposition reactions over these new Fe/Ni catalysts.

Leaching behavior of the boron (B) and fluorine (F) present in fly ashes formed in pulverized coal combustion has been studied with a batch-type quartz vessel under the conditions of 25 °C and a solution to solid ratio of 100 ml/g according to the Dutch Standard NEN 7341 method (availability test). When each ash sample is stirred in ultra pure water without any acids, the pH of the resulting aqueous mixture is as high as 11-12 in every case, whereas the leaching of B-containing ions or F- ions depends strongly on the type of the ash, and the corresponding leaching extent after 60 min-stirring is in the range of 20 % to 65 % and 15 % to 45 %, respectively. In the experiments at a constant pH of 1.5-9.0 of a fly ash with relatively-high B (1000 μg/g-dry) and F (130 μg/g-dry) contents, more than 70 % of B in the ash is leached rapidly within 10 min, and the rate is larger at a lower pH condition. The leaching of F- ions also occurs within 10 min, and the extent depends significantly on pH and increases in the order of pH 9.0 (32 %) ≈ pH 5.6 (35 %) < pH 1.5 (72 %) < pH 3.0 (80 %). The concentration of the B or F present in each ash sample after acid leaching at pH 1.5 - 2.0 is less than the corresponding regulation limit for water pollution. Several factors determining the leachability of these elements are investigated.

Aiming to understand the formation mechanism of dioxins in the iron ore sintering process, dust samples obtained from some windboxes of a commercial iron ore sintering plant have been characterized with a powder X-ray diffraction (XRD), by the transmission electron microscope (TEM) equipped with an electron energy loss spectroscopy (EELS), and by the temperature-programmed desorption (TPD) and temperature- programmed oxidation (TPO) techniques. The elemental and XRD analyses reveal that the content of the Cl present in the samples ranges from 0.075 mass%-dry to 5.1 mass%-dry and tends to be higher at smaller dust particles, and that some of the Cl exists as KCl with the average crystalline size between 40 nm and 50 nm. Dust samples also contain a significant amount of unburned carbon, and the smallest dust particles

Mesoporous molecular sieves (MCM-41 and SBA-15) with different pore diameters have been studied as supports of high loading of Co catalysts, and the performances in FT synthesis have been examined with a fixed bed stainless steel reactor at 2.0 MPa for the purpose of efficient production of C10–C20 fraction as the main component of diesel fuel. The method of exchanging template ions in uncalcined MCM-41 with Co2+ ions is effective for holding 10–20% Co within the mesopores while keeping the structure regularity of MCM-41 to some extent, compared with the conventional impregnation method using calcined MCM-41. At 523 K, CO conversion and selectivity to C10–C20 hydrocarbons are both higher at larger loading of 20% Co for the exchanged catalysts with pore diameters of 2.7–2.9 nm. When four kinds of 20% Co/SBA-15 with the diameters of 3.5–13 nm, prepared by the impregnation method using an ethanol solution of Co acetate, are used in FT synthesis at 523 K, the catalyst with the diameter of 8.3 nm shows the largest CO conversion, which is higher than those over MCM-41 supported Co catalysts. At a lower temperature of 503 K, however, the acetate-derived Co is almost inactive. In contrast, the use of Co nitrate alone or an equimolar mixture of the acetate and nitrate as Co precursor drastically enhances the reaction rate and consequently provides high space–time yield (260–270 g C/kgcat h) of C10–C20 hydrocarbons. The X-ray diffraction and temperature-programmed reduction measurements show that the dependency of the catalytic performance of 20% Co/SBA-15 on its precursor originates probably from the differences in not only the reducibility of the calcined catalyst but also the dispersion of metallic Co. Catalyst characterization after FT synthesis strongly suggests the high stability of the most effective Co/SBA-15 in the dispersion and reducibility of the oxide species and in the mesoporous structure.

Hydrocracking of petroleum asphaltene with Fe and Ni catalysts loaded on SBA-15 supports has been carried out with a stainless autoclave at 573 K in pressurized H 2 . Asphaltene conversion with 10 wt.% Fe catalysts with average pore diameters of 4.5–15 nm increases with increasing pore diameter up to 12 nm and reaches about 70%, but levels off beyond this value. Maltene yield shows the same dependency on the diameter and the highest value of 40% at 12–15 nm. When metal loading in the Fe catalyst with the pore diameter of 12 nm is varied between 4 and 30 wt.%, asphaltene conversion and maltene yield are the largest at 4 and 10% Fe, respectively, indicating the presence of the optimum Fe loading for maltene formation. The use of the 10% Ni catalyst in place of the 10% Fe catalyst lowers the conversion slightly but improves selectivity to maltene greatly. This means that the Ni is suitable for selective conversion of asphaltene to maltene, probably because of higher hydrogenation ability. The X-ray diffraction (XRD) measurements of toluene-insoluble (TI) fractions recovered after hydrocracking and the analyses of SO 2 evolved during the temperature-programmed oxidation (TPO) reveal the formation of Fe–S and Ni–S phases as surface species. The catalysis of asphaltene conversion by the sulfided forms is discussed.

Binary oxides, mainly Ca-Mn, Sr-Mn and Ba-Mn, have been studied as catalysts for the coupling of CH 4 to C 2 hydrocarbons (C 2 H 6 and C 2 H 4 ) using CO 2 as oxidant. At temperatures of ≧840°C, the Ca-Mn catalyst exhibits quite similar performances to those of other Ca-containing binary oxide catalysts (Ca-Ce, Ca-Cr and Ca-Zn) reported previously; C 2 selectivity and yield at 850°C increase remarkably with increasing partial pressure of CO 2 , and apparent activation energies observed over these catalysts are roughly the same (190–220 kJ mol −1 ). When the temperature is decreased from 840 to 825°C, CH 4 conversion and C 2 selectivity over the Ca-Mn catalyst abruptly drop; here a discontinuous change also is seen in the Arrhenius plots. On the other hand, the Sr-Mn and Ba-Mn catalysts show different kinetic features from the Ca-Mn system; C 2 selectivity at 850°C changes only slightly with partial pressure of CO 2 , and the activation energies are constant over the whole temperature range examined and notably lower. Characterizations reveal that solid solution of Ca 0.48 Mn 0.52 O is the main phase for the Ca-Mn catalyst after reaction at 850°C, while, at 800°C, some Ca 2+ ions separate from the solid solution to form CaCO 3 , which covers the catalyst surface. Such a difference probably accounts for the discontinuous change in the catalytic behavior with temperature. With the Sr-Mn and Ba-Mn catalysts, SrCO 3 and BaCO 3 are formed along with MnO after reaction, and the carbonates are suggested to react with MnO to form SrMnO 2.5 and BaMnO 2.5 in the conversion process of CH 4 with CO 2 . The mechanism for C 2 formation involving SrMnO 2.5 and BaMnO 2.5 as intermediates is discussed.

Several types of SBA-15 with pore diameters of 3.6–12 nm have been synthesized under different reaction conditions, followed by air calcination, and utilized as supports for loading 10–20 mass% Co catalysts. Post-synthesis heat treatment after reaction at 308 K is more effective for increasing the pore diameter and volume of SBA-15 than the addition of trimethylbenzene before reaction. The combination of the two results in the formation of SBA-15 with large pore diameter but broad size distribution and less organized structures. When an acetone, ethanol, or water solution of Co(NO 3 ) 2 is used as a precursor for impregnation with SBA-15 with pore diameter of 3.6 nm, the average crystalline size of Co 3 O 4 observed at 10 mass% Co exceeds the pore diameter irrespective of the kind of the solvent. On the other hand, the use of an ethanol solution of Co(CH 3 COO) 2 or an acetone solution of (CH 3 COCHCOCH 3 ) 2 Co provides no X-ray diffraction peaks of Co 3 O 4 even at loading as high as 20 mass% Co, and catalyst addition considerably decreases the pore volume of SBA-15 support regardless of the pore diameter. These observations strongly suggest that Co catalysts exist as nanosized clusters inside the mesopores. The SAXS measurements show that the hexagonal mesoscopic organization of the SBA-15 support with pore diameter of 5.5 nm is almost retained even after addition of 20 mass% Co. The 20 mass% Co/SBA catalysts are also tested preliminarily in Fischer–Tropsch synthesis under 503–523 K and 2.0 MPa.

A binary catalyst of CaO-ZnO is effective for the selective conversion of CH{sub 4} to C{sub 2} hydrocarbons using CO{sub 2} as the oxidant. C{sub 2} selectivity approaches 80% with a C{sub 2} yield of 4.3% over the catalyst with a Ca/Zn ratio of 0.5 at 875 C. The lattice oxygen of the CaO-ZnO converts CH{sub 4} mainly to H{sub 2} and CO. The presence of CO{sub 2} forms a new oxygen species, which is active and selective for the conversion of CH{sub 4} to C{sub 2} hydrocarbons. The CaO component in the catalyst enhances the adsorption of CO{sub 2} and thus suppresses the reaction involving the lattice oxygen. The reduced Zn site is suggested to activate CO{sub 2}.

Gasification of petroleum coke with metal hydroxide catalysts has been carried out in CO2 at 850°C with a thermobalance. KOH is impregnated with coke, and Ca(OH)2 and fine particles of FeOOH are separately mixed with coke in water, metal loading being 3wt% in every case. Fixed carbon conversion excluding volatile matter was 7% and 55% after 120min without and with Fe, respectively, and it reaches 100% after 60min and 70min with K and Ca, respectively. Thus, K and Ca catalysts can promote the gasification remarkably. Initial rates per remaining carbon with K and Ca are as great as 50 and 100 times that without catalyst, respectively. The extent of rate enhancement by K addition is larger at the latter part of reaction, because the rate of K-catalyzed gasification increases exponentially with increasing fixed carbon conversion. When the samples after 50% conversion are subjected to X-ray diffraction measurements, the K is most highly dispersed among the three catalysts, and their presence lowers carbon crystallinity, irrespective of type of catalyst. Since inexpensive Ca(OH)2 is remarkably effective by simple mixing with coke in water, and is higher in thermal stability than KOH, which is known to vaporize readily as metal as the gasification proceeds, it can be concluded that the Ca is the most promising catalyst in coke gasification.

Conversion of methane and carbon dioxide into ethane and ethylene (C2 hydrocarbons) has been performed over terbium (Tb) oxide catalysts. Effectiveness of catalyst is influenced by precursor of the oxide; a Tb oxide prepared from the nitrate shows the highest C2 yield, whereas, an oxide from the oxalate gives the highest C2 selectivity. Since CO yield increases with increasing specific surface area of the Tb oxide, attributed to the successive oxidation of C2 hydrocarbons formed from CH4, lower specific surface area is favored for formation of C2. Examining the effects of reaction conditions on the performance of the catalyst from Tb nitrate, it was found that the highest C2 yield and selectivity are obtained at 1173K and 1073K, respectively, and higher C2 selectivity was observed at higher partial pressure of CH4.

Selectivity and yield of ethane and ethylene in the conversion of methane without O2 increased remarkably with increasing partial pressure of carbon dioxide over CeO2 modified with CaO. The chemisorbed carbon dioxide is proposed to be responsible for the selective formation of ethane and ethylene.

The highlight of this review article is a novel method to remove fuel-bound nitrogen as N2 during coal pyrolysis in an inert atmosphere. When a Cl-free iron catalyst is precipitated on Australian brown coal from FeCl 3 solution using Ca(OH) 2 , N2 yield increases with increasing pyrolysis temperature and reaches 50% at 900°C, whereas it is < 5% without the iron. A low loading (1 wt% Fe) is sufficient for the remarkable formation of N2, and the use of H2 instead of inert He is unnecessary. The iron catalyst decreases the partitioning to not only volatile nitrogen (tar, HCN, and NH3) but also char nitrogen. A smaller catalytic effect of the precipitated iron is observed with bituminous coal. The iron catalyst after pyrolysis exists as fine particles with a smaller size of 20-30 nm for the brown coal char, Fe3C and graphitized carbon being also present. It is likely that N2 originates mainly from solid phase reactions involving the formation and subsequent decomposition of iron nitrides. In the pyrolysis of different coals at 1000°C, N2 yields for low-rank coals from China and Germany reach 50-60% despite the absence of catalyst. Demineralization with HCI washing removes mainly Fe and Ca elements from these coals and drastically decreases N2 yield with a corresponding increase in nitrogen retention in the chars. The Ca ion-exchanged with the demineralized coals is inactive for N2 formation. Iron nanoparticles, derived from Fe-containing minerals, catalyze predominantly solid phase reactions to extract N2 from char and/or precursors.

The present review article focuses on novel methods of converting inexpensive raw materials to active catalysts for low-temperature coal gasification, which can produce clean fuels and valuable feedstock with high thermal efficiency. Precipitation methods using NH3, urea, and Ca(OH)2 make it possible to prepare active, Cl-free iron catalysts on brown coals from an aqueous solution of FeCl3 as the major component in acid wastes. The use of Ca(OH)2 provides the most active iron, which achieves complete gasification within 60 min in a thermogravimetric run at 973 K. Ca(OH)2 and CaCO3 are other promising catalyst sources. Ca(OH)2 promotes the steam gasification of many coals with different ranks at 973 K when kneaded with them in water. The calcium shows a larger catalytic effect for low-rank coals with higher contents of oxygen-functional groups as ion-exchangeable sites. CaCO3, as a raw material of Ca(OH)2, reacts with COON groups to form ion-exchanged Ca and CO2 when mixed with brown coals in water. Ion-exchange reactions proceed more readily with aragonite naturally present in seashells than with calcite from limestone. The exchanged calcium shows higher catalytic activity than the precipitated iron and provides at the largest 40–60-fold rate enhancement during steam gasification at 973 K. Catalysis of coal gasification by the iron and calcium is discussed in terms of catalyst dispersion, reactive sites, and sulfur poisoning.

Catalytic effectiveness for the synthesis of ethane and ethylene from methane and carbon dioxide has been examined mainly at 1123 K over 14 lanthanide oxides. Praseodymium (Pr) and terbium oxides show high yield and high selectivity of C2 hydrocarbons among lanthanide oxides. The catalytic performances of Pr oxides are influenced by the preparation method; a commercial Pr oxide prepared from the oxalate shows the highest C2 selectivity of about 50%, and the stable performance for 20 h. Higher partial pressures of CO2 and CH4 are favorable for C2 formation over the oxide catalyst. Reaction mechanisms over Pr oxides are discussed in terms of a redox mechanism involving the unstable lattice oxygen.

Ethane and ethylene are formed by the reaction of CH4 and CO2 over unsupported manganese oxide catalysts mainly at 1123 K. CH4 conversion (5-15 mol%) and C2 yield (0.1-0.4mol%) depend greatly on their starting materials. C2 yield with β-MnO2 incrcascs gradually with time on stream, whercas that with e-MnO2 decreases. The yicld with β-MnO2 increases with rise in temperature to a larger extent. Manganese oxide catalysts change chemically in the same manner; β-MnO2 and e-MnO2 are transformed into Mn2O3 in air at 1123 K, then to Mn3O4 upon switching from air to N2, and finally to MnO during reaction. The formation of C2 hydrocarbons is discussed in terms of a redox mechanism involving the lattice oxygen atoms of manganese oxides.

Conversion of methane with carbon dioxide has been performed over seventeen metal oxides using a flow reaction system at 1123 K. The conversion ratio of carbon dioxide to methane is approximately two in most cases. Ethane and ethene (C 2 hydrocarbons) are formed over many oxides, and C 2 yield is higher over yttrium and manganese oxides. Rare earth catalysts such as yttrium, lanthanum, and samarium show higher C 2 selectivities of about 30%. C 2 selectivity is almost unchanged over yttrium and zirconium oxides during reaction while it decreases over samarium oxide. X-ray diffraction analysis reveals that some oxides such as manganese and iron oxides are reduced during reaction. The reaction mechanism for C 2 formation is discussed in terms of both adsorbed oxygen species dissociated from carbon dioxide and the lattice oxygen in metal oxides.

As a model study on the synthesis of natural products possessing an eight-membered cyclic ether or amine framework such as laurencin (1) and FR900482 (6), two kinds of 2-benzyl oxacyclooctanones (7 and 8) and 2-methyl azacyclooctanones (9 and 10) were synthesized from the corresponding twelve-membered lactam sulfoxides (49-52) by applying our general method for medium-ring ketone synthesis. The corresponding lactam sulfides were readily prepared from the linear ω-tosyl carboxylic acids containing on oxygen atom (11 and 12) or methylcarbamate group (13 and 14) by condensation with 2-cyanoethyl 2-N-methylaminophenyl sulfide followed by alkylation.

A stereocontrolled total synthesis of natural (+)-cis-α-irone (1) is described. The key intermediate (±)-hemiacetal 15 was prepared from the diene 10 in six steps. The crucial optical resolution of (±)-15 was achieved by initial stereoselective conversion into the corresponding l-menthyl acetals 16 and 17 followed by separation and hydrolysis. One of the optically pure enantiomers of 15 was transformed to (-)-18 and then to (+)-1 in seven steps. The synthetic (+)-1 was found to be identical with the natural (+)-cia-α-irone. The isomeric (-)-cis-α-irone was also synthesized from the other enantiomer of 15, via (+)-18.

Stereocontrolled synthesis of two twelve-membered lactam sulfides 37 and 38 as precurors of 8, 11, 11-trimethyl-3-oxobicyclo[5.3.1]undec-8-enes constituting the A and B rins of taxane-diterpenes was achieved.The keystep involves a Diels-Alder reaction of maleic anhydride and the E-diene 18 for introduction of the requisite cis arrangement of substitutions at the C-1 and C-7 positions.The resulting adduct was converted exclusively into the lactone 21b in five steps : 1) hydrolysis, 2) iodo-lactonization, 3) BH3 reduction, 4) Zn reduction, 5) methylation.The benzyl group of 26 could be selectively removed by heating with Raney Ni(W-2) in EtOH in nearly quantitative yield without hydrogenation of the double bond.

Conformational restrictions of sangivamycin (1) could be achieved by the use of the gauche effect of the substitutents on the ribofranose moiety. The conformational deviations obtained by this method were found to nicely correlate with the inhibitory activity of PKC.

The structures of new antifungal antibiotics, PF1163A and B, were elucidated by spectroscopic analyses of the degradation products and by X-ray crystallography of the de-2-hydroxyethyl derivative of PF1163B. Both antibiotics consist of a 13-membered macrocyclic structure containing a derivative of N-methyl tyrosine and a hydroxy fatty acid. PF1163A differs from PF 1163B by having an additional hydroxyl group on the side chain.

An effective general method for the construction of medium-ring ketones from the corresponding ω-bromocarboxylic acids is described. When the diamide disulfide 10 was treated with NaBH4 and NaH in 2-propanol, reductive cleavage of the sulfur-sulfur bond and concomitant intramolecular coupling of the resulting thiolate anion with the terminal bromide took place and the large-ring lactam sulfide 7, which was the key intermediate for the synthesis of medium-ring ketones, was obtained. Although lithium diisopropyl amide (LDA) treatment of 11 followed by reductive desulfurization provided cycloundecanone (13d) in only 19.5 % yield, intramolecular cyclization of the α-methylated analogues 17 with LDA proceeded smoothly and the keto sulfoxides 18 were obtained in quantitative yields. In the case of the lactam sulfones 21, tert-BuOK was effective as a base for the intramolecular cyclization, affording the keto sulfones 22 in quantitative yields. The keto sulfoxides 18 and sulfones 22 were subjected to reductive desulfurization with Al-Hg to yield medium-ring ketones 19 and 13, respectively, in high yields.

すでに,筆者らは化学物質を経口投与することによって,4眠性の交雑種から3眠蚕を出現させうることを,コウジ酸やその関連物質で見い出していたが,今回,アビエチン酸と37種の関連化合物および16種のヒドロフルオレン系化合物の3眠蚕出現活性を調べたところ,それらのあいだに,コウジ酸より強い活性を示す化合物を見い出すことができた。すなわち,供試化合物を200ppm添加した人工飼料を4齢起蚕より連続投与したところ,アビエチン酸誘導体で3種,ヒドロフルオレン系化合物で11種のものが3眠蚕を出現させた。そして,これらの化合物のあいだで,構造-活性相関について若干の知見が得られた。上記14種の化合物のうち,9種類については,100ppmでも3眠蚕出現活性が認められた。最も強い活性を示した〔A-11〕 (methyl 6, 7-dioxo-5α, 10α-podocarpa-8, 11, 13-trien-15-oate)は,50ppmでも3眠蚕を出現させた。また,この化合物の100ppm添加飼料を3齢起蚕より連続投与したところ,無添加区が5齢になった時点でも,多くの幼虫が3齢のままで生存することがわかった。

Catalytic oxychlorination of methane was investigated with the equimolar binary melts of potassium chloride with cupric chloride and ferric chloride in a flow reactor under atmospheric pressure at temperatures of 340 to 410 °C. The methane conversion was higher and depended on reaction time considerably with the cupric chloride system, whereas there was little time-dependence with the ferric chloride system. This difference between the above two systems was discussed in view of the reaction mechanism. It was found that, with the cupric chloride system, the selectivity to higher chlorinated products was greater than that obtained in the thermal chlorination and in the chlorination with melts used by previous investigators, and furthermore that the activity decreased drastically at the solidification point.

Intramoleclar acylation of the sulfur-stabilized carbanions of the acyclic ester 9 and amide sulfides 11 was carried out as a model study for developing an effective method for the construction of medium-ring ketones by ring closure. Reaction of 9a-c or 11a-g with lithium diisopropylamide (LDA) proceeded smoothly and the expected keto sulfides 10a-c or 12a-g, respectively, were obtained. In the cases where R1 and/or R2 in 11 were normal alkyl groups, the reaction did not take place. However, these difficulties were readily overcome either by introducing a methyl group next to the carbonyl group or by converting the sulfides into the corresponding sulfoxides or sulfones. Acylation in the allyl sulfides 11b, d, f and the allyl sulfone 20b takes place at the α-position to the sulfur atom, yielding β, γ-unsaturated ketones. A reductive removal of the sulfide moiety or its conversion into other functional groups was also examined.

In the previous study it was found that the nickel catalyst impregnated on brown coals shows excellent activity in the gasification reaction. In this study more cheap catalyst, Ca (OH) 2, was used as starting material. The chemical state during the steam gasification was determined and the reactivity was determined in the temperature range from 600 to 800°C. Ion-exchanged Ca was transformed to finely dispersed CaCO3 upon pyrolysis and the extensive crystal growth of CaCO3 was observed during the course of steam gasification. Near the end of gasification CaCO3 was converted to CaO owing to the decrease of CO2 content in the atmosphere. About 2 wt% of Ca content was enough to enhance the reactivity of coal by a factor of 10 at 650°C. In order to obtain the same reaction rate, 750°C is necessary without catalyst. This catalytic effect was more significant when compared with the data for the Ca-catalyzed gasification of American low-rank coals.

The catalytic cracking of slack wax with molten mixtures of AlCl3 and AlBr3 was investigated in an atmospheric semi-batch reactor at low temperatures of 100–160 °C. The cracking rate was proportional to the amount of unreacted wax. The conversion at 135 °C reached 25 wt% under typical reaction conditions. About 95 wt% of the cracking products consisted of isobutane, 2-methylbutane, and methylpentanes, ca. 50% of these isoparaffins being isobutane. The difference in cracking activity between this catalyst and a solid acid catalyst is discussed based on the product distribution. Hardly any reaction took place without HCl, which shows that the presence of HCl is essential for this cracking. The cracking rate increased sharply with an increase in the amount of the catalyst. The rate did not depend on the composition of the AlCl3–AlBr3 catalyst, but the product distribution did depend on it and the content of the gasoline fraction in the products increased with an increase in the concentration of AlBr3. The cr...

Pyrolysis and steam gasification of Yallourn brown coal with Na, Ca and Ni catalysts were carried out in a fluidized bed reactor at 1.1MPa. The Na or Ca ion was loaded on the coal by the ion-exchange method using NaCl or Ca (OH) 2 solution, and Ni catalyst was impregnated from Ni (NH3) 6CO3 solution. When the coal was pyrolyzed in N2 stream at 1.1MPa, the weight loss was smaller in the presence of these catalysts because of a smaller evolution of tar. The tar was decom-posed to carbon and gaseous materials with the Ni, and it was converted into gas at higher temperatures with the Na and Ca.These catalysts promoted the steam gasification of brown coal under pressurized atmospheres. The addition of Ni, Na and Ca lowered the gasification temperature by 220, 70 and 150K, respectively. The reactivity of Ni-loaded coal levelled off at around 970K and the coal conversion of 80%, whereas the reactivity of Ca-loaded coal increased with temperature and the conversion reached 93% at 1080K. The conversion of coal carbon to gas and the total amount of product gas were considerably larger for the catalyst-loaded coals, because these catalysts promoted the reaction of tar with H2O as well as the gasification of char. The Ni catalyst was found to be more suitable for the direct produc-tion of methane by the reaction between brown coal and steam, and the Ca catalyst was suitable for the production of H2-rich gas. It was also found that the gasification catalyst could be used to control the H2/CO ratio in product gas.

In order to find a better method of catalyst addition for gasification of coals, some new or improved methods have been developed by our laboratory.As one of them, nickel and potassium carbonate were impregnated on the surfaces of four coals oxi-dized by nitric acid at 40t.The amount of nickel actually loaded on oxidized coals was much larger than on original coals.The better dispersion of nickel particles on the char surface of oxidized Leopold coal was observed by scanning electron microscope.An eight-fold increase in the concentration of carboxyl functional groups was obtained on the oxidized coal.Therefore the better dispersion is due mainly to the increased amount of nickel ion combined with these groups.The rates of steam gasification of the catalyst-impregnated coals were much higher with oxidized coals than with original coals.For example, when 2.0% of catalyst metal was impregnated on Shin-Yubari coal, the ratio of initial gasification rate with the oxidized coal to that with the original one at 750t was 2.0 for nickel and 3.8 for potassium carbonate.The finely dispersed catalyst on oxidized coals may lead to the higher gasification rate.An extraordinary high activity of nickel catalyst was observed when it was impregnated on coals which had a large amount of carboxyl groups.

Morphologic analysis was made on early whorls of two Paleozoic and 43 Mesozoic ammonoid species to obtain basic data on early life history. A positive linear relationship between protoconch and ammonitella sizes is recognized among the species examined. Total rotation angle of the ammonitella (ammonitella angle) seems to be independent of ammonitella size but has a significant negative linear relation with whorl expansion rate. This supports the model that the embryonic shell of ammonoids consists of gas-filled protoconch and the succeeding body whorl up to the primary varix. Growth analysis of siphuncle diameter in the early post-embryonic stage also indicates that the shell growth rates of the species hatched from large-sized eggs were smaller than those of species hatched from small-sized eggs.

Catalytic cracking of Taching vacuum residue was investigated in a semi-batch reactor at low temperatures ranging from 100 to 170°C under atmospheric pressure. Aluminum chloride with hydrogen chloride was mainly used as the catalyst. Most of the products were light isoparaffins from C4 to C7. Cracking conversion depended on such process parameters as reaction time, amount of catalyst, hydrogen chloride, and temperature. The optimal conversion was about 50 wt% with the AlCl3-HCl system. This value hardly changed regardless of variation in the above parameters. Infrared spectra of the reaction residue revealed that disappearance of the methylene chain signal led to the ceasing of cracking. These findings showed that only the paraffinic chains present in the Taching residue were catalytically cracked at as low temperature as 150°C.

Using the readily obtainable 11-nitrophenol 5 prepared by selective nitration of the 12-hydroxy ester 4, syntheses of taxodione (1), royleanone (2) and their analogues (7 and 8) having the methoxy-carbonyl group in place of the 4α-methyl group were accomplished.

A new method for preparing β, γ-unsaturated ketones based on the intramolecular acyl N to C transfer of 2-carboxamidephenylsulfides is described including a total synthesis of egomaketone using this method.