Hydrolysis amines

An improved version of the amine hydrolysis process involves catalytic hydrogenation of 1,3,5-triaitrobenzene or 2,4,6-triaitrobenzoic acid in acetone solvent (138). Acid hydrolysis of 2,4,6-triaminobenzoic acid has been improved by addition of copper catalyst and gives phlorogluciaol in 80% yield (139). 

Basicity also may be regarded as a measure of amine hydrolysis, and it governs the increase in pH level, per additional unit measure of amine. The law of diminishing returns applies of course, and beyond a certain point there is little further increase in system pH. Also, the basicity constant for individual amines varies considerably with temperature, so it is important to consider Kb at the relevant operating temperature, rather than simply at ambient temperature. 

The final pH, after neutralization, is determined by the remaining amine hydrolysis (basicity constant). 

Heterocyclic Chemistry (CHEC-I). Reactivity of 1,3,2-dithiazole-5-ones, -thiones, -imines, and 1,3,2-oxathiazole-5-ones is also much more widely covered than in CHEC-I, their thermolysis, photolysis, oxidation, methylation, amination, hydrolysis, 1,3-cycloaddition, etc. are discussed. 

This strategy was further developed so as to prepare the quinolizidine polyol 155 (315), by separating the racemic furoisoxazoline acetals (21,82,293,294) derived from the imidazolidine derivatives, which in turn, were obtained from (15, 25)-diphenylethylenediamine (316) (see Scheme 6.78). Aminal hydrolysis led to aldehyde 153, and this was followed by aldehyde reduction and catalytic hydrogenation (221,313) to give (-l-)-deoxynojirimycin (natural). Its enantiomer was... 

Transamination. Addition of a proton to the carbonyl carbon of the pyri-doxal leads to a compound that is the Schiff base of an a-keto acid and pyridox-amine. Hydrolysis of the Schiff base gives the a-keto acid and pyridoxamine, which may react with a different a-keto acid to reverse the sequence ... 

As we have indicated in Section 23-12, amide hydrolysis can be an important route to amines. Hydrolysis under acidic conditions requires strong acids such as sulfuric or hydrochloric, and temperatures of about 100° for several hours. The mechanism involves protonation of the amide on oxygen followed by attack of water on the carbonyl carbon. The tetrahedral intermediate formed dissociates ultimately to the carboxylic acid and the ammonium salt ... 

Dethiation Alkylation and acylation Halogenation Amination Hydrolysis Oxidation... 

The reaction used to inhibit the enzyme is our old friend, reductive amination. The amino group on the lysine is the most nucleophilic in the enzyme because it is involved in the active site and it forms an imine with the aldehyde. Reduction fixes the aldehyde to the enzyme as a secondary amine. Hydrolysis of the protein reveals a new amino acid in place of that lysine. This particular aldehyde was used because it contains a UV-active (actually coloured) p-nitrophenol so that the modified amino acid can be found among the many natural amino acids. 

Keywords carbofunctional organosilicon amines, hydrolysis, reetherification... 

The usual acid derivatives of 5-oxo-2-pyrazolin-3- and 4-carboxylic acids are known. Amides are prepared by reaction of esters and ammonia,1339 by the reaction of urea with 2-pyrazolin-5-ones, and by the reaction of azides with ammonia and amines. Hydrolysis of nitriles... 

In Fig. 6 carbon dioxide reactions are categorized by industrially important products. Hydrogenation reactions produce alcohols, hydrocarbon synthesis reactions produce paraffins and olefins, and amine synthesis produces methyl and higher-order amines. Hydrolysis reactions can produce alcohols and organic acids. Carbon dioxide serves as an oxygen source in the ethyl benzene to styrene reaction. It can be used in dehydrogenation and reforming reactions. 

Diamine 264 is made from the a-diketone benzil by a simple but multiple cyclisation to give the heterocycle 265. Stereoselective dissolving metal reduction gives anti-266 and hence racemic 264 on aminal hydrolysis. Resolution with tartaric acid brings down crystals of the tartrate of one enantiomer. With l-(+)-tartaric acid, the salt with (.S, .S )-264 is less soluble while (R,R)-264 requires treatment with d-(—)-tartaric acid. One important application is the asymmetric Lewis acid46 267. 

Mustard (nitrogen) HN Tris(2-chloroethyl)amine Hydrolysis products... 

Many useful methods have been pubHshed for the determination of trace isocyanates in air and in polyurethane products by derivatization and GC, LC, or SEC quantification. For example, industrial hygiene determination of TDI in air by OSHA method 42 is performed by drawing air through a filter impregnated with l-(2-pyridyl)piperazine. Derivatives are formed during sampling, which are then determined by LC. Also of concern are the amine hydrolysis products of the isocyanates. For example, toluenediamine (TDA) may be monitored in furniture foam. This is generally accomplished by liquid-solid extraction or vacuum distillation, followed by GC or LC quantification. 

To complete the total S3mthesis of ent-staurosporine (2), a two-step deprotection strategy (hydrogenation followed by aminal hydrolysis) delivered 64 from 63 in high yield (Scheme 8). Danishefsky et al. preferred to clarify the monosaccharide domain prior to reducing the maleimide function [45], The most efficient method involved reduction of the imide group with sodium borohydride to provide a mixture of hydroxy lactams. Further reduction... 

In aqueous base, the products of amide hydrolysis are a carboxylate salt and ammonia or an amine. Hydrolysis in aqueous base is driven to completion by the acid-base reaction between the resulting carboxylic add and base to form a salt. One mole of base is required per mole of amide. 

Scheme 47 Two-step amination/hydrolysis sequence for aminocyclotryptamine 53b.

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