1,2,3,4-Tetrahydro-3-methyl-2,4-dioxo5-trimethylsilylethynyl-quinazoline → 4,5-Dihydro-4-methyl-3-(5-methyl-1,2,4-oxadiazol-3-yl)-5-oxo-imidazo(1,5-a)quinazoline

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A mixture of 4,5-Dihydro-4-methyl-3-(5-methyl-1,2,4-oxadiazol-3-yl)-5-oxo-6-trimethylsilylethynyl-imidazo(1,5-a)quinazoline, M.p. 214°-217° C., and 6-ethynyl-4,5-dihydro-4-methyl-3-(5-methyl-1,2,4-oxadiazol-3-yl)-5-oxo-imidazo(1,5-a)quinazoline, M.p. 202°-206° C., by reaction between 5-methyl-3-isocyanomethyl-1,2,4-oxadiazole and 1,2,3,4-tetrahydro-3-methyl-2,4-dioxo-5-trimethylsilylethynyl-quinazoline. Column chromatography(silica gel)/ethyl(acetate) of the crude product yielded 0.08 g (12%) of 4,5-dihydro-4-methyl-3-(5-methyl-1,2,4-oxadiazol-3-yl)-5-oxo-imidazo(1,5-a)quinazoline and 0.01 g (1.9%) of 6-ethylnyl-4,5-dihydro-4-methyl-3-(5-methyl-1,2,4-oxadiazol-3-yl)-5-oxo-imidazo(1,5-a)quinazoline.

Provenance & Evidence