N1-Substituted-5-amino-4-cyanopyrazoles were cyanoacetylated with a mixture of cyanoacetic acid and acetic anhydride. Cyclization with POCl3 gave 4-chloro-pyrazolo[3,4-d]pyrimidine derivatives. From the reaction with hydrazine and arylhydrazines, the hydrazinyls and their oxidized forms, the azo products, were obtained. The structure of the compounds obtained has been confirmed by 1H and 13C NM...

The acetylation of aryl ethers using acetic anhydride in the presence of zeolites under modest conditions in a solvent-free system gave the corresponding para-acetylated products in high yields. The zeolite can be recovered, regenerated and reused to give almost the same yield as that given when fresh zeolite is used.

A bismuth bromide-catalyzed (10.0 mol %) multicomponent reaction involving the allylation of THFand THP-ethers, followed by in situ derivatization with acetic anhydride to generate highly functionalized esters has been developed under solvent-free conditions. To the best of our knowledge, this is the first report of a catalytic procedure for the allylation of THFand THPethers to yield ring-open...

The wide-spread use of photoelectric calorimeters in the field of quantitative clinical chemistry has brought with it the realization that many of the visual calorimetric methods in use are grossly inaccurate and that their use may be justified only on the basis of an arbitrary range of normal values for the given procedure. This is particularly true in the case of total cholesterol values whic...

Coumarins are a class of compounds with benzopyrone ring system. In the present work 7-hydroxy-4-methyl coumarin was prepared by the reaction of resorcinol and ethylacetoacetate mixture in the presence of concentrated sulphuric acid. 7-hydroxy-4-methyl coumarin was acetylated with acetic anhydride in the presence of acetic acid. The product formed was treated with bromine in glacial acetic acid...