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The starting substrate 5-chloro-4,9-dimethoxy-7-oxo-7H-furo[3,2-g]chromene-6-carbonitrile (2) was efficiently synthesized from chlorination of the corresponding hydroxy derivative. The presence of adjacent cyano and chloro functions was employed for construction a variety of five, six and seven membered rings annulated furo[3,2-g]chromenes. Treating precursor 2 with hydrazine, phenylhydrazine and hydroxylamine yielded furo[3,2:6,7]chromeno[4,3-c]pyrazoles 3, 4 and furo[3,2:6,7] chromeno[3,4-d]isoxazole 5, respectively. Also, reaction of compound 2 with a diversity of 1,3-N,N-binucleophiles such as guanidine, cyanoguanidine, thiourea, acetamidine and benzamidine produced annulated furo[3,2:6,7]chromeno[4,3-d]pyrimidines 6–10, respectively. Further, treatment of compound 2 with a variety of 1,4-binucleophiles namely ethylenediamine, o-phenylenediamine and 2-aminophenol yielded furo[3,2:6,7]chromeno[4,3-e][1,4]diazepine 11, furo[3,2:6,7]chromeno[4,3-b][1,5]benzodiazepine 12 and furo[3,2:6,7]chromeno[4,3-b][1,5]benzoxazepine 13, respectively. Some of the synthesized compounds seemed good antimicrobial activity especially compounds 3, 6 and 8. Using analytical and spectral results, the structures of the prepared compounds were established. [ABSTRACT FROM AUTHOR]

Halogenations are the most important transformations in organic synthesis and can be carried out by several methods. In particular, the electrochemical reactions serve as an excellent method for the generation of reactive species under mild conditions which do not require large quantities of toxic or corrosive reagents. This review outlines the significant developments in the area of electrochemical methods over conventional in the synthesis of aryl halides, particularly in the recent two decades. [ABSTRACT FROM AUTHOR]

A series of "drug-like" compounds based on quinoxaline scaffold with arylsulfonyl hydrazinyl, arylformyl hydrazinyl or arylsulfonyl groups at C-2 and aryloxy groups at C-3, were synthesized in 4 or 5 steps involving cyclization, chlorination and coupling reactions. Cellular anti-proliferative activities of these quinoxaline derivatives in vitro were determined, which revealed that the inhibitory potency and selectivity of 6f was comparable to that of the positive control. [ABSTRACT FROM AUTHOR]

A convenient, rapid H2SO4-promoted regioselective monobromination reaction with N-bromosuccinimide was developed. The desired para-monobrominated or ortho-monobrominated products of phenol derivatives were obtained in good to excellent yields with high selectivity. Regioselective chlorination and iodination were also achieved in the presence of H2SO4 using N-chlorosuccinimide and N-iodosuccinimide, respectively. [ABSTRACT FROM AUTHOR]

The sulfenylchlorination of a series of alkenes is investigated by using the combined reagent of dimethyl sulfoxide and oxalyl chloride. The corresponding β-chloro sulfides were obtained in mediate to good yields. Most of the terminal alkenes give the Markovnikov adducts mainly and the sulfenylchlorination of cyclic alkenes is stereospecific to produce the adducts with trans configuration. Methanesulfenyl chloride is supposed to be the real species for sulfenylchlorination. [ABSTRACT FROM AUTHOR]

The sulfenylchlorination of a series of alkenes is investigated by using the combined reagent of dimethyl sulfoxide and oxalyl chloride. The corresponding β-chloro sulfides were obtained in mediate to good yields. Most of the terminal alkenes give the Markovnikov adducts mainly and the sulfenylchlorination of cyclic alkenes is stereospecific to produce the adducts with trans configuration. Methanesulfenyl chloride is supposed to be the real species for sulfenylchlorination. [ABSTRACT FROM AUTHOR]

NMP-mediated chlorination of aliphatic alcohols has been developed for the synthesis of alkyl chlorides. This facile, efficient and practical approach used simple and readily available aryl sulfonyl chlorides as the chlorination reagent for the construction of C-Cl bond in good to excellent yields with mild conditions and broad substrate scope. [ABSTRACT FROM AUTHOR]

A simple and selective copper(II) chloride-mediated monochlorination of anilines and nitrogen-containing heterocycles has been developed. Stirring a mixture of aniline, copper(II) chloride, lithium chloride in EtOH under reflux condition produced 4-chloroaniline with high yield. Eighteen substrates including substituted anilines, N-substituted anilines, N,N-disubstituted anilines, 5-nitroindole and carbazole were all reactive and afforded desired products in moderate to excellent yields (52%-98%). [ABSTRACT FROM AUTHOR]

An efficient and concise approach to the total synthesis of Paecilomycins E (1) and F (2), Cochliomycin C (4) and 6-epi-Cochliomycin C (3) is described. The synthesis involves novel route to the synthesis of Paecilomycin E and F and further conversion to Cochliomycin C and 6-epi-Cochliomycin C. Olefin metathesis and base promoted macro lactonization being the key reactions followed by chlorination to achieve target Cochliomycin C and 6-epi-Cochliomycin C. [ABSTRACT FROM AUTHOR]

This paper mainly studied Pd-catalyzed regioselective chlorination of disubstituted 1,2,3-triazoles directed by the 1,2,3-triazole ring. A series of regioselective chlorinated products were synthesized in 47-86% yields using Pd(OAc)2 as a catalyst and CuCl2 as a chlorinated reagent. This method provides a new mean for the synthesis of 1,2,3-triazole halides which combines the formation of C-X bond with C-H activation. [ABSTRACT FROM AUTHOR]

Phenols are easily converted to the corresponding aryl chlorides by using phosphorus pentachloride (PCl5) and a catalytic amount of phenylphosphonic dichloride (PhPOCl2), which is a new efficient method for synthesis of aryl chloride in good yields. [ABSTRACT FROM PUBLISHER]

The treatment ofN-alkyl-5-nitroindazole with stannous chloride in ethanol, aftercoupling of the obtained amines with arylsulfonyl chloride in pyridine, gave the new 4-ethoxy- and 4-chloroindazoles bearing sulfonamide in moderate to good yields. Chlorination and ethoxylation of indazole were observed during the reduction of the nitro group with anhydrous SnCl2in ethanol. The influence of theN-alkylation in N-1 and N-2 position of 5-nitroindazole on the reduction was investigated. The presence ofethoxy group and chlorine atom at position C-4 of indazole was confirmed by x-ray diffraction analysis of compounds7aand8a. [ABSTRACT FROM AUTHOR]

New convenient method for synthesis of p-chlorinated calix[4]arenes is reported. The sulfuryl chloride was used for chlorination of unsubstituted at the lower rim calix[4]arenes. The products of this reaction were very suitable for further O-alkylation. [ABSTRACT FROM AUTHOR]

The novel dual use of formamide-POCl3 mixture for the incorporation of a C-N fragment to form the pyrimidine nucleus and its subsequent chlorination in an efficient, one-pot synthesis of potentially bioactive condensed 2H-pyrimidin-4-amine libraries under microwave irradiation (MWI) is reported. The one-pot microwave-assisted synthetic protocol is high-yielding, ecofriendly, rapid, and novel as well as eliminates intermittent workups. The protocol can be adapted for the library synthesis of series of a condensed pyrimidines. [ABSTRACT FROM PUBLISHER]

Chlorination of commercially important aromatic compounds using sodium chloride as chlorine source and sodium periodate as oxidant in acidic medium catalyzed by sodium lauryl sulfate (SLS) led to the chloro-substituted aromatics in good yields and purity. Addition of sodium lauryl sulfate led to increased chlorination rate, better yield, excellent purity, and better quality of end product. The advantages of the present method are greater yield, excellent purity, and shorter reaction time at room temperature. Also dichlorinated product can be obtained by increasing the amount of sodium chloride and sodium periodate at slightly higher temperature (40 °C). [ABSTRACT FROM AUTHOR]

An improved synthesis of ximenynic acid (1) starting from castor oil has been developed with the direct chlorination of ricinstearolic acid as the key step. By this modification, the synthetic route was more concise and economic. The separation of geometric somers was achieved by repeated urea fractionation. Supplemental materials are available for this article. Go the publisher's online edition of Synthetic Communications to view the free supplemental file. [ABSTRACT FROM AUTHOR]

Ceric ammonium nitrate (CAN) has been found to be a remarkable oxidizing agent for the oxidative conversion of iodoarenes to (dichloroiodo)arenes in acetic acid using aqueous HCl. The reaction of CAN with HCl generates in situ molecular chlorine, which is responsible for the oxidation. This method avoids the use of hazardous, toxic, and corrosive gaseous chlorine. [ABSTRACT FROM AUTHOR]

Two benzoxazinone compounds as epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors were synthesized and characterized by NMR and high-resolution mass spectrometry (HRMS). An efficient chlorination method was introduced in the synthesis of 4-chloro-2-oxo-2H-benzoxazinone-6-yl acetate. The inhibition activities of the target compounds and the important intermediates for EGFR tyrosine kinase activity in vitro were determined. [ABSTRACT FROM AUTHOR]

A large scale synthesis of valdecoxib 1 is described. Our work features potential application of [3 + 2]-dipolar cycloaddition involving enamine and in situ–generated nitrile oxide derivatives. [ABSTRACT FROM PUBLISHER]

A novel 2-methylsulfanyl-4H-[1,2,4]triazolo[1,5-a]quinazolin-5-one was synthesized using dimethyl-n-cyanoimidodithiocarbonate and 2-hydrazinobenzoic acid as building blocks. Chemical transformation of the inherent lactam moiety in the targeted 2-methylsulfanyl-[1,2,4]triazolo[1,5-a]quinazolin-5-one offered access to a variety of derivatives.[image omitted] [ABSTRACT FROM AUTHOR]

New quinoxaline derivatives were prepared by the reaction of 2-hydroxyquinoxaline 1 and alkyl or alkylaminoalkyl halides in dimethylformamide using potassium carbonate as a base. The hydroxyl group was readily converted into a thiol function by treatment with phosphorus pentasulfide and/or Lawesson's reagent in pyridine, and the subsequent alkylation of the thiol group was carried out under phase-transfer catalyst conditions. Chlorination of 1 was carried out with phosphorus oxychloride. Branching of alkylamino side chains to the 2-OH, 2-SH, and 2-Cl quinoxalines resulted in the synthesis of several compounds. Synthesis and alkylation of 2-hydroxy 7-nitroquinoxaline are also reported. [image omitted] [ABSTRACT FROM AUTHOR]

[image omitted] Alkyl aryl ketones on treatment with SiCl4/urea-hydrogen peroxide (UHP) or SiCl4/iodosylbenzne reagent systems afforded α-chloroketones in excllent yields, while ketones with higher enol content provide exclusively α,α-dichloroketones under exceedingly mild conditions. The reaction proceeds via the initial formation of silyl enol ethers. A polarized chlorine intermediate that resulted from the coordination of SiCl4 with the in situ formed trichlorosilyl hypochlorite Cl3SiOCl is thought to be the active chlorinating agent. [ABSTRACT FROM AUTHOR]

Aniline undergoes regioselective trichlorination by N-chlorosuccinimide (NCS) in acetonitrile in good yield. The product 2,4,6-trichoroaniline was converted into 1,3,5-trichlorobenzene by reduction of its diazonium salt. Reaction of the methyl carbamate of aniline with NCS gave only the 2,4-dichlorophenyl carbamate. [ABSTRACT FROM AUTHOR]

Oxidation of 2-aryl-2,3-dihydro-4(1H)-quinolones (1) with 1.5 equivalents of (dichloroiodo)benzene in dichloromethane at room temperature leads to regioselective chlorination, thereby offering an efficient method for the synthesis of new 2-aryl-6-chloro-2,3-dihydro-4(1H)-quinolones (3). [ABSTRACT FROM AUTHOR]

Regiospecific chlorination of xylenes has been developed by employing NCS as a reagent and K-10 montmorrillonite clay as a solid support. [ABSTRACT FROM AUTHOR]

An unexpected aromatization of 2-acetoxy-3,3-dichloro-4-(α-chloroalkyl)tetrahydrofurans to 3-alkyl-4-chlorofurans occurs on heating with sodium iodide in dimethylformamide (DMF) at 120 °C. [ABSTRACT FROM AUTHOR]

The preparation of benzimidazole compound 7, an ORL-1 agonist, is described. The four-step procedure gave the compound 7 in 29% overall yield. [ABSTRACT FROM AUTHOR]

A series of dendritic phenol ether derivatives with a naphthalene core were synthesized by the Williamson reaction as a coupling reaction between 1-hydroxymethylnaphthalene and polyether-based dendritic fragments in the presence of phase-transfer catalyst and alkali. The modified method for chlorination of dendritic benzyl alcohol was also developed using PPh3 and CCl4 as reagents and CH2Cl2/CCl4 as solvent. [ABSTRACT FROM AUTHOR]

An improved synthetic approach to tenatoprazole 1 is described. It started from 2,3,5-trimethyl-4-nitropyridine-N-oxide 2 with acetic anhydride via rearrangement and hydrolysis to give 3, Chlorination with SOCl2 yielded 2-chloromethyl-3,5-dimethyl-4-nitropyridine hydrochloride 4, then 4 condensed with 2-mercapto-5-methoxy imidazole [4,5-b]pyridine 5 to give 5-methoxy-2-[(4-nitro-3,5-dimethyl-2-pyridinyl)methylthio]imidazole[4,5-b]pyridine 6. At last the title compound 1 was produced by two methods: 6 was oxidized with MCPBA and then methoxylated with CH3ONa to give 1 and 6 was first methoxylated with CH3ONa and then oxidized with MCPBA to give 1. The overall yield is around 26% for both five-step syntheses. [ABSTRACT FROM AUTHOR]

A concise and efficient total synthesis of Secobatzelline B is reported. The synthesis involves eight steps starting from known 4,6,7-trimethoxyindole. Synthetic tactics involve a one-step reduction of an indole-3-glyoxalic ester using LiAlH4, resulting in complete reduction of the ester group and a partial reduction of the vinylogous amide carbonyl group. Synthesis also involves the use of a mixture of NaCl and oxone as a new reagent for regioselective chlorination of an indoloquinone derivative. [ABSTRACT FROM AUTHOR]

The first total synthesis of the chlorinated 1-oxo-β-carboline alkaloid bauerine C based on a Japp-Klingemann reaction is reported. An intermediate of this synthesis was converted to the fully aromatic β-carboline bauerine B, and the related alkaloid bauerine A was prepared in an analogous manner. [ABSTRACT FROM AUTHOR]

A facile and efficient method for the α-halogenation of carbonyl compounds utilizing N-halosuccinimides (NXS) in the presence of urea–hydrogen peroxide (UHP) in [bmim]BF4 has been newly developed. [ABSTRACT FROM AUTHOR]

The influence of diverse carboxylic acid on the preparation of chlorohydrin esters using a one-pot esterification–chlorination reaction, in which one of the reagents (chlorotrimethylsilane) acts as solvent, is described. Whereas the acid with low pKa provided higher amounts of the 2-chloro regioisomer, the ones with higher pKa rendered the 1-chloro regioisomer in 80% yield. These results are in accordance with the mechanism proposed in a previous article. [ABSTRACT FROM AUTHOR]

Effective a-chlorination reactions of aryl ketones into the corresponding a-chloroketones have been accomplished with aluminum chloride hexahydrate and urea–hydrogen peroxide in [bmim]BF 4 ionic liquid. [ABSTRACT FROM AUTHOR]

A novel method for the synthesis of a-chloroacetophenones using 1,3-dichloro-5,5-dimethylhydantoin (DCDMH) and p -toluenesulfonic acid in methanol at 30–35°C is described. Substituted acetophenones at the para position or meta position of aromatic ring give a-chloroacetophenones in high yield. However, reaction of o -nitroacetophenone does not take place under the same condition. [ABSTRACT FROM AUTHOR]

High‐yield reductive homocoupling of benzotrichloride and benzal chloride followed by consecutive reductive dechlorination to 1,2‐dichlorostilbene and stilbene is effected in the presence of sodium formate as the reducing agent and Pd/C catalysts. [ABSTRACT FROM AUTHOR]

Amides are efficiently converted to N ‐chloroamides by trichloroisocyanuric acid in methanol. [ABSTRACT FROM AUTHOR]

Amides are chlorinated on the nitrogen using trichloroisocyanuric acid, and the N ‐chloroamides are then rearranged to the corresponding methyl N ‐substituted carbamates by sodium methoxide in methanol. [ABSTRACT FROM AUTHOR]

This article describes a convenient preparation of diethyl (2‐thienyl)methanephosphonate in 88% overall yield. [ABSTRACT FROM AUTHOR]

Microwave‐assisted reaction using phosphonium salt for dehydration of primary amides and chlorination of hydroxyheteroaromatics was carried out. [ABSTRACT FROM AUTHOR]

We have synthesized and characterized a series of alkyl and aryl‐(4‐methyl‐6‐nitro‐quinolin‐2‐yl)amines through a high‐yield, three‐step procedure starting from 4‐methylquinolin‐2‐ol. Nitration using concentrated nitric/sulfuric acids, followed by chlorination in phosphorus oxychloride, yielded 2‐chloro‐4‐methyl‐6‐nitro‐quinoline. All of the intermediates and aminated products have been characterized by multinuclear ( 1 H and 13 C) NMR spectroscopy, elemental analysis, and, in the case of the two title compounds (ethyl and cyclohexyl‐(4‐methyl‐6‐nitro‐quinolin‐2‐yl)amine), a single crystal X‐ray structure was obtained to verify the nature of the new materials. [ABSTRACT FROM AUTHOR]

Synth. Commun. 2005, 35 , 1983 Microwave‐Assisted Dehydration and Chlorination using Phosphonium Salt Ken‐ichi Tanji, Jiro Koshio, and Osamu Sugimoto Laboratory of Organic Chemistry, School of Food and Nutritional Sciences, University of Shizuoka, 52‐1 Yada, Shizuoka 422‐8526, Japan [ABSTRACT FROM AUTHOR]

Chlorination of 1-bromo-2-fluoroethylene followed by reductive dehalogenation of the produced 1-bromo-1,2-dichloro-2-fluoroethane selectively affords 1-chloro-2-fluoroethylene. This process is suitable to produce 37Cl isotopically enriched ClHC[dbnd]CHF on a convenient scale (3.8 mmol). [ABSTRACT FROM AUTHOR]

Carboxylic acids are chlorinated in the α position by heating with trichloroisocyanuric acid after formation of a small amount of the acid chloride using phosphorus trichloride. [ABSTRACT FROM AUTHOR]

Electron rich arylmethylsulfonyl chlorides can be prepared from arylmethyl bromides by phase transfer sulfonation and chlorination with PCl5. [ABSTRACT FROM AUTHOR]

Aryl and enolizable alkyl ketones react with copper(II) chloride in dimethylformamide to produce the corresponding α,α-dichloroketone in high yields. Remarkable qualities of the process are high selectivity towards these substrates, undetected polychlorinated by-products, easy work-up, commercially available reagents and HCl as the only waste stream. [ABSTRACT FROM AUTHOR]

N-Chloro-2,3,4,4,5,6-hexachlorocyclohexa-2,5-dienylideneamine was used as a new, mild and highly regioselective chlorinating reagent in the chlorination of phenol and o-cresol in CCl4, DMF and CH3CN. The effects of C2H5OH, C5H5N, DMF and Et3N on the regioselectivity in CCl4 have also been examined. [ABSTRACT FROM AUTHOR]

A highly efficient, regioselective method for oxychlorination of aromatic compounds is possible through electrophilic substitution of chlorine generated in situ from KCl as a chlorine source and Oxone® as an oxidant for the first time. [ABSTRACT FROM AUTHOR]

Regiospecific chlorination of pyridine-N-oxide to give 2-chloropyridine was achieved in 90% yield with 99.2% selectivity by treatment with phosphorus oxychloride in the presence of a stoichiometric amount of triethylamine. Other chlorinating agents such as sulfuryl chloride, p-toluenesulfonyl chloride, trichloroacetyl chloride, benzenesulfonyl chloride and methanesulfonyl chloride produced 2-chloropyridine also under these conditions, albeit in moderate yield. [ABSTRACT FROM AUTHOR]