Synthesis of a 3-Acetoxy-6-phenylpyrone and Its Conversion to a Pyrido-(1,4)benzodiazepine.

3-Acetoxy-6-(2-nitro-3,4,5-trimethoxyphenyl)-4-pyrone was prepared via condensation of 3-acetoxy-4-methoxy-3-buten-2-one with the appropriate benzoyl chloride and acid catalyzed cyclization. The intermediate pyrone was converted to the target, 6-oxo-2,5,9,10,11-pentamethoxy-1,2,3,6-tetrahydropyrido [1,6-d] [1,4] benzodiazepine