(4-Nitrophenyl)acetic acid → 7,8-Dimethoxy-6-nitro-3-(4-nitro-phenyl)-chromen-2-one

Participants

Reaction Steps

A solution of 2-hydroxy-3,4-dimethoxy-5-nitro-benzaldehyde obtained from Preparation Example (1a) (0.46 g), 4-nitrophenyl acetic acid (0.39 g) and triethylamine (0.84 ml) in 1,2-dichloroethane (30 ml) was treated with phenyl dichlorophosphate (0.44 ml) at 0° C. The mixture was refluxed for 5 hours and cooled. The cool reaction mixture was diluted with methylene chloride, washed successively with 2.5 M NaOH, 2 M HCl and water, dried and evaporated. The product was finally triturated with pethroleum ether and filtered. Yield: 0.52 g, melting point 219-223° C.

Provenance & Evidence