Sodium borohydride → tert-Butyl 6-hydroxy-2-azaspiro[3.3]heptane-2-carboxylate

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Reaction Steps

0.494 g (13.06 mmoles) of sodium borohydride is added in portions at 0° C. to a solution of 2.30 g (10.89 mmoles) of tert-butyl 6-oxo-2-aza-spiro[3.3]-heptane-2-carboxylate, obtained in stage 10.2, in 55 ml of methanol. The reaction mixture is stirred for 1 hr at ambient temperature. After evaporation of the solvent, water is added to the reaction mixture, the aqueous phase is separated, it is extracted several times with dichloromethane, and the combined organic phases are washed with a saturated aqueous solution of sodium chloride, dried over sodium sulphate and the filtrate is concentrated under reduced pressure. After crystallisation of the residue in diisopropyl ether, filtration of the solid obtained and drying under vacuum at 60° C., 2.24 g of product are obtained in the form of a beige powder.

Provenance & Evidence