Dimethyl Sulfoxide → HCID 20211025, compound

Participants

Reaction Steps

To a stirred solution of 72 parts of ethanedioyl dichloride in 650 parts of dichloromethane were added, during a period of 10 minutes, 83.5 parts of dimethyl sulfoxide at -60° C. and under nitrogen atmosphere. After stirring for 10 minutes, a solution of 97 parts of 3,4-dihydro-5,7-dimethyl-2H-1-benzopyran-2-methanol in 130 parts of dichloromethane was added during a 5 minutes period. The whole was stirred for 15 minutes and 242.9 parts of N,N-diethylethanamine were added. The reaction mixture was allowed to reach room temperature. It was poured into water. The product was extracted with dichloromethane. The extract was washed successively with water, a hydrochloric acid solution 10%, water, a sodium hydrogen carbonate solution 10% and water, dried, filtered and evaporated. The oily residue was crystallized from a small amount of petroleumether. The product was filtered off and dried, yielding 58 parts (72%) of 3,4-dihydro-5,7-dimethyl-2H-1-benzopyran-2-carboxaldehyde (intermediate 34).

Provenance & Evidence