Water → 2,2-Dimethyl-2H-chromen-6-amine

Participants

Reaction Conditions

Reaction Steps

Ten grams (10 g, 48.7 mmol) of 2,2-dimethyl 6-nitro 2H-1-benzopyran (3) was dissolved in 60.0 g of ethanol under heating. After cooling to 35° C., 0.6 g of 2% Pt—C (50% water-containing product) was added thereto, and 5.85 g (117.0 mmol) of hydrazine monohydrate (98% product) was added dropwise (dropwise adding was continued for 30 minutes) while controlling internal temperature to 40° C. or less. After completion of dropwise adding, reaction was carried out at a temperature of 40 to 45° C. for 6 hours. The resulting solution was cooled to room temperature, and then 10.0 g of water was added thereto and the resulting solution was filtered through celite. The celite was washed with 20.0 g of 80% water-containing ethanol, and the washing together with the filtrate were subjected to solvent-distillation. The residue was extracted with 40.0 g of toluene and 20.0 g of water. After separating into phases, the aqueous phase was extracted with 20.0 g toluene again. The toluene phases were combined, washed with 20.0 g of water and then subjected to solvent-distillation to obtain a crude product of intended product (4).

Provenance & Evidence