The present paper is intended as a contribution to the specific chemistry of the naturally occurring hydroxyamino acids. Certain established differences in the chemistry of the acyl derivatives of amino and hydroxy groups have so far not been utilized in the study of hydroxyamino acids, and in particular no simple method for the preparation of their 0-acetyl derivatives has been developed. The ...

INTRODUCTION The inability of acetic anhydride to acetylate pulp efficiently in the absence of a catalyst has received much attention from different research workers. In fact the acetylation with acetic anhydride is unsuccessful if pre-activation has not been carried out. It can be assumed that the energy of interaction between acetic anhydride and cellulose in the absence of a catalyst is insu...

An exothermic reaction, leading to 3-(2-furyl)acrylic anhydride and a little amount of furfurylideneacetone is taking place when reacting 3-(2-furyl)acrylic acid in acetic anhydride above 120°C. The 3-(5-acetyl-2-furyl)acrylic acid was formed under the afore-mentioned conditions only in the presence of H 3 P 0 4 . The 3-(2-furyl)acrylic anhydride is more stable towards HNO, at temperatures unde...

A series of 3,5-disubstituted pyrazole-1-carboxamides were obtained by treatment of chalcones with semicarbazide hydrochloride in dioxane containing sodium acetate/acetic acid as a buffer solution. N-acetyl derivatives of pyrazole-1-carboxamides were isolated in good yields either by treatment of the carboxamide derivatives with acetic anhydride or refluxing chalcones with semicarbazide in etha...

The present paper is intended as a contribution to the specific chemistry of the naturally occurring hydroxyamino acids. Certain established differences in the chemistry of the acyl derivatives of amino and hydroxy groups have so far not been utilized in the study of hydroxyamino acids, and in particular no simple method for the preparation of their 0-acetyl derivatives has been developed. The ...

A Zn-salen-modified cavitand templates the catalytic formation of acetylcholine from choline and acetic anhydride.

An acetic anhydride pyridine mixture acetylates hydroxyl groups in tissue sections. The acetyl groups can be removed from tissue sections by weak alkali. Sections acetylated by acetic anhydride pyridine no longer produce aldehydes after oxidation by periodic acid. Acetylated sections subjected to weak alkali regain the ability to produce aldehydes after oxidation by periodic acid. Acetylation o...

The cationic ring-opening polymerization reaction of tetrahydrofuran at 20 degrees C was catalyzed by H3PW12O40 x 13 H2O as solid acid catalyst. The effect of the proportions of acetic anhydride and catalyst, reaction time and support on the polymerization reaction was investigated. It has been found that the yield and the viscosity of the polymer depend on the proportion of acetic anhydride, t...

Aim: Dimedone , gamma pyrone and barbituric acid and their derivatives have also been found to be very important from their application point of view. Thus our aim was to prepare more derivatives from them. Method : Dimedone , gamma pyrone and barbituric acid have been treated with dimethyl sulphoxide and acetic anhydride reagent under varying temperature conditions in order to get more compoun...