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The complex formed from acetic sulfuric anhydride (CH3COOSO2OH, ASA) and water has been observed by pulsed nozzle Fourier transform microwave spectroscopy. ASA was formed in situ in the supersonic jet via the reaction of SO3 and CH3COOH, and subsequently complexed with water using a concentric, dual injection needle that allows reagents to be introduced at different points along the expansion axis. Spectroscopic constants for the parent, fully deuterated, and CH313COOSO2OH species are reported. Both A and E internal rotor states have been observed and analyzed. The fitted internal rotation barrier of the methyl group is 219.598(21) cm–1 for the parent species, indicating that complexation with water lowers the internal rotation barrier of the methyl group by 9% relative to that of the free ASA. M06-2X/6-311++G(3df,3pd) calculations predict at least two distinct isomeric forms of ASA···H20. Spectroscopic constants for the observed species agree with those for the lower energy isomer in which the water inse...

Tetramethylammonium hydroxide was used as a base instead of a traditional inorganic base in this copper-catalyzed system and some satisfactory results were obtained. Various functional groups were compatible under this reaction condition.

The amination of aryl halides in the presence of inexpensive and air-stable alkali metal hydroxide bases and Pd[P(t-Bu)3]2 as catalyst gave arylamines in high yields. The reactions were conducted with a catalytic amount of cetyltrimethylammonium bromide as phase-transfer agent and either aqueous hydroxide or solid hydroxide in the presence of water. This combination of alkali metal hydroxide base, H2O, and the ammonium salt performed as well as NaO-t-Bu in the amination of p-chlorotoluene with dibutylamine. Hydroxide base was suitable for reactions of a wide range of aryl chlorides and bromides with aliphatic and aromatic amines. Some functional groups that were intolerant of tert-butoxide base, such as esters, enolizable ketones, nitriles, and nitro groups, were tolerated by the combination of hydroxide base, H2O, and cetyltrimethylammonium bromide in toluene solvent.

Conjugate addition of methanol to 3-buten-2-one to form 4-methoxy-butan-2-one proceeds effectively over the solid base catalysts such as alkaline earth oxides, strontium hydroxide, barium hydroxide, and alumina supported potassium fluoride and hydroxide at a reaction temperature of 273 K. The catalytic activities of magnesium oxide, calcium oxide, and alumina supported KF catalyst were not much affected by exposure of the catalysts to carbon dioxide or air.

The reaction of a set of primary and secondary amines with acetic anhydride in water at 25 o C gave variable yields of the N-substituted acetamide in seven of the eight amines studied. The yield of the amide as a function of pH revealed the incursion in most cases of a general base assisted hydrolyse of the acetic anhydride by the amine. From the pK a 's of the amines and k w and k OH for acetic anhydride (the specific rates for the reaction of the anhydride Nth water and hydroxide, respectively), both k DN (for the formation of the acetamides) and l GB (for the general base assisted hydrolysis) may be readily evaluated by fitting the pH-yield data to pH-yield or pH-product ratio profiles

The complexation between lead(II) and hydroxide has been studied in molten (K,Na)NO3 at 280 °C by various techniques. An inert platinized platinum wire bathed with a gaseous mixture of oxygen and water served as a hydroxide electrode in potentiometric determinations of the hydroxide activity in the melts. Only PbOH+ and Pb2OH3+ can be detected at the low hydroxide concentrations used. Raman spectra and 1H NMR experiments gave strong indications that hydroxide retains the proton also when coordinated to lead(II). Oxide ions added to the melts readily transform into hydroxide even at very low water activities. Studies of the solubility of Pb(NO3)2 in melts with various concentrations of dissolved PbO show the formation of [PbOH+]q-species at fairly high hydroxide concentrations. Liquid X-ray scattering data yield q= 2 at these hydroxide concentrations, i.e. Pb2(OH)2+2 is the predominant complex ion. The Pb—O and Pb—Pb distances are 2.7 and 3.4 A, respectively. The short Pb—Pb distance is the same as that observed in the halide species Pb2X3+, and it is suggested that the complex is stabilized by a Pb—Pb interaction.

1. Weak CH acids: p-nitrotoluene, o-nitrotoluene, α-, β-, and γ-picolines, α- and β-methylnaphthalenes, and p-toluenechromiumtricarbonyl are oxidized by oxygen in a basic medium. 2. The most effective system is dimethoxyethane-18-crown-6 ether-potassium hydroxide, in which it is possible to attain the maximum yields of acids. 3. On increasing the oxygen pressure, the oxidation of p-nitrotoluene can be carried out successfully in the benzene-dimethylsulfoxide-potassium hydroxide and methanol-sodium hydroxide systems.

It was shown by means of the UV spectra that a sydnoneimine base is formed from 3-cyclohexylsydnoneimine hydrochloride by the action of an equivalent amount of sodium hydroxide in solutions of absolute alcohols. The sydnoneimine base is also formed in the case of solvolysis of N6-trimethylsilyl-3-cyclohexylsydnoneimine in methanol. The sydnoneimine base in solutions exists in equilibrium with the chain isomer, viz., the nitrile. The fraction of the cyclic isomer increases as the electron-donor properties of the substituent in the 3 position become more pronounced.

The solubility of Ge(OH) 2 was measured in dilute solutions of perchloric acid and sodium hydroxide and in water at 25°C. Apparently this oxide does not form true solutions in sodium hydroxide as evidenced by the formation of a deep red colour both in the solid and in the liquid media. Other observations also indicate that colloids form.

N-Formylsarcosine-N-methylthioamide is transformed into 1,3-dimethyl-4-mercaptoimidazolium ion on treatment with trifluoroacetic acid in acetonitrile, while the thioformyl analogue produces 3-methyl-5-methylaminothiazolium ion under the same conditions. The latter ion rearranges irreversibly to the former in aqueous acid or, in base, to its deprotonated derivative, anhydro-1,3-dimethyl-4-mercaptoimidazolium hydroxide. Aqueous base deformylates N-formylsarcosine-N-methylthioamide, while aqueous or non-aqueous bases convert the thioformyl analogue into anhydro-1,3-dimethyl-4-mercaptoimidazolium hydroxide. N-Formyl- and N-thioformyl-sarcosine-N-methylthioamide yield 3-methyl-5-acylmethylaminothiazolium salts when treated with acetyl chloride or trifluoroacetic anhydride. The trifluoracetylaminothiazolium salt is readily deacylated. Mechanisms are elucidated by means of deuterium exchange experiments. The reaction of 5-methylthiothiazolium salts with amines has been rationalized.

A rapid path for the hydration of acetaldehyde is demonstrated, in which a zinc complex and the hydroxide ion co-operate as catalysts. In the mechanism proposed a zinc-bound hydroxide ion attacks directly the carbonyl group of the aldehyde. Comparison of the nucleophilic strengths of hydroxide ions in various complexes demonstrates a correlation similar to that obtained by other workers for attack on propionic anhydride and on carbon dioxide. The enzyme carbonic anhydrase behaves consistently with this correlation for the substrate acetaldehyde, but not for the substrate carbon dioxide.

The kinetics of the spontaneous and the acid-catalysed hydrolysis of thiolbenzoic anhydride and of the aminolyses of thiolbenzoic, benzoic, thiolacetic, and acetic anhydrides with substituted anilines in dioxan–water mixtures have been examined. Thiolbenzoic anhydride is more easily hydrolysed than benzoic anhydride, but its hydrolysis is less sensitive to acid catalysis. It is also less sensitive to salt effects than that of thiolacetic anhydride. It is concluded generally that bond-breaking plays a more important part in the hydrolyses of the benzoic anhydrides than in those of the acetic derivatives. The aminolyses studied were all first-order in aniline, a result which excludes general base catalysis by the free base. With any given base, and for a given type of anhydride, the sulphur derivative always reacts faster than its oxygen analogue, the rate ratio decreasing as the basic strength of the aniline is increased. The data support the contention that the spontaneous hydrolyses are subject to general base catalysis by other water molecules, and that the attacking nucleophile is incipiently formed hydroxide ion. The results for acetic and thiolacetic anhydrides substantiate the view that in acylation an increase in nucleophilicity of the attacking reagent leads to an increase in the kinetic importance of the bond-forming process. The data as a whole support our previous generalisations about acylation.