Oxidative aminobenzaldehyde

Unsubstituted quinazoline 3-oxide was prepared in an attempt to react quinazoline with hydroxylamine. This reaction gave a product of variable composition, but when an acetone solution was heated in a sealed tube it gave quinazoline 3-oxide. The oxide is more conveniently prepared, in excellent yield, from o-aminobenzaldehyde oxime and ethyl orthoformate. This method appears to be of general use and has been used for the preparation of 4-methylquinazoline... 

Depending upon the structure of the substrates 49, 52, and 56 hexahydropyrido[l,2-n]-[3,l]benzoxazines 50, 54, 2-aminobenzaldehyde 53, 1-substituted piperidones 51, 55, 57, 3,4,5,6-tetrahydropyridinium salt 58, or their mixture was obtained during the oxidation of 1-(2-hydroxymethyl-, 2-formyl- and 2-acetylphenyl)piperazines (49, 52, 56) with Hg(II)-EDTA complex (Schemes 6-8) (79AP219, 98ZN(B)37, 98ZN(B)1369). 

Collagen determination. In order to calculate the amount of collagen in a sample, hydroxyproline was measured in acid hydrolyzates (Jamall et al., 1981). After oxidation, hydroxyproline reacts with p-dimethyl-aminobenzaldehyde to give a red colour, which is measured by spectrophotometry. For bovine dentin, collagen mass was estimated as 8.0 x the hydroxyproline value as calculated from previous data (Volpin and Veis, 1973). To calculate the molar quantities of collagen, a molecular mass of 300 kDa was used. 

Similar reducing effects are obtained from alkali sulfides, hydrosulfides and polysulfides [241]. A peculiar reaction believed to be due to sodium polysulfide formed in situ by refluxing sulfur in aqueous-ethanolic sodium hydroxide is a conversion of p-nitrotoluene to p-aminobenzaldehyde [242]. Oxidation of the methyl group by the polysulfide generates hydrogen sulfide which then reduces the nitro group to the amino group. 

Amide reduction with lithium aluminum hydride, 39, 19 Amine oxide formation, 39, 40 Amine oxide pyrolysis, 39, 41, 42 -Aminoacetanilide, 39, 1 Amino adds, synthesis of, 30, 7 2-Amino-4-anilino-6-(chloro-METHYl) -S-TRIAZINE, 38, 1 -Aminobenzaldehyde, 31, 6 hydrazone, 31, 7 oxime, 31, 7 phenylhydrazone, 31, 7 > -Aminobenzoic add, 36, 95 2-Aminobenzophenone, 32, 8 c-Aminocaproic acid, 32, 13 6-Aminocaproic acid hydrochloride,... 

Diamine oxidase (DAO) activity could be determined by first reacting cadaverine with an enzyme to produce A1-piperidine, which then was reacted with 2-aminobenzaldehyde and finally chromium(VI) oxide to form 6,7,8,9-tetrahydro-ll//-pyrido[2,l-b]quinazolin-ll-one (7). The latter was determined on an HPLC apparatus (Scheme 5) (84MI4). 

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