Sodium borohydride → HCID 14580514, compound

Participants

Reaction Steps

10.2 g of sodium borohydride were added in portions at 0° C. with vigorous stirring to a suspension of 50 g of 3,4-dihydro-7-nitro-1-benzoxepin-5(2H)-one (J. Chem. Soc., Perkin Trans. 1 (1991), 2763) in 345 ml of methanol. After 30 min, the reaction mixture was added to ice water, the solid was filtered off with suction and 43 g of 7-nitro-2,3,4,5-tetrahydro-1-benzoxepin-5-ol was obtained. This was heated on a water separator for 2 h with 1 g of p-toluenesulfonic acid in 520 ml of toluene. After cooling, the organic phase was washed with sodium bicarbonate solution and sodium chloride solution. After drying over sodium sulfate and concentrating, 38.8 g of 2,3-dihydro-7-nitro-1-benzoxepine were obtained, m.p. 98-100° C.

Provenance & Evidence