4-Methoxy-8-nitro-dibenzo[b,d]furan-1-carboxylic acid → 4-Methoxy-8-chloro-dibenzo[b,d]furan-1-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

Intermediate 29 (350 mg, 1.13 mmol) was suspended in mixture of concentrated hydrochloric acid:water (1: 1) (5 ml) and stirred at 50° C. for 30 min. The suspension was cooled to 0° C. and a solution of sodium nitrite (83 mg, 1.2 mmol) in water (2 ml) was added dropwise in 15 min. The reaction was stirred for 90 min. at 0-5° C. and then this suspension was added to a pre-cooled solution of CuCl (123 mg, 1.24 mmol) in concentrated HCl (5 ml). The reaction was allowed to come to room temperature and further heated to 80-90° C. for 2 h. The reaction mixture was then poured into water (100 ml) and the solid was filtered and then purified by column chromatography using 20% ethyl acetate-chloroform as the eluent to obtain 250 mg of the product as white solid; mp: 264-276° C.

Provenance & Evidence