反应详情

35.5 g of borane-trimethylamine complex and then, slowly and while cooling to 10° C., 40.55 ml of 12N hydrochloric acid aqueous solution were added to a solution of 22.8 g of the product of Step A in 570 ml of dioxane and the mixture was stirred for 16 hours at ambient temperature. It was poured into 1,500 ml of water, washed with ethyl acetate, made alkaline with 48 ml of concentrated ammonia and was extracted with ethyl acetate. The organic phases were dried, filtered and evaporated to dryness to obtain 22.6 g of methyl N-[2-(2,3-dihydro-1H-indol-4-yl)-2-hydroxyethyl]carbamate which was crystallized from methanol to obtain 13.125 g of the product melting at ≃174° C.

1. washwashed with ethyl acetate
2. extractionwas extracted with ethyl acetate
3. customThe organic phases were dried
4. filtrationfiltered
5. customevaporated to dryness