Benzopyrones. Part 17. The synthesis of some bischromones and the reaction of cyanomethyl esters with sodium azide
Abstract
Treatment of 4-oxochromen-2-carbonyl chloride with dimethylcadmium gave 1-methyl-1-(4-oxochromen-2-yl)-ethyl 4-oxochromen-2-carboxylate (11) which was synthesized unequivocally and degraded to the carboxylic acid and 2-(1-methylvinyl)chromen-4-one. 2-Acetylchromen-4-one was synthesized by a new and more efficient method from 4-oxochromen-2-carbonyl chloride.
The synthesis and some reactions of 4-oxochromen-2-yl isocyanate, and the cyanomethyl esters of 4-oxochromen-2-carboxylic and -2,6-dicarboxylic acids are described.