Dichloromethane → Trans-6-Cyano-3,4-dihydro-2,2-dimethyl-4-(N-methylureido)-2H-1-benzopyran-3-ol

Participants

Reaction Steps

Trans-4-amino-6-cyano-3,4-dihydro-2,2-dimethyl-2H-1-benzopyran-3-ol (2.00 g) in dichloromethane (30 ml) was added dropwise to a stirred solution of methyl isocyanate (0.54 ml) in dichloromethane (15 ml), the temperature being maintained at below 10° C. After 15 min a white precipitate formed and the reaction mixture was allowed to reach room temperature. The solid was filtered and recrystallised from dichloromethane to give the title compound (1.30 g) as crystals of m.p. 143°-146° C.

Provenance & Evidence