Sodium borohydride → (7S,8S,9R)-2,3-Dimethyl-8-benzyl-7,8-dihydroxy-9-phenyl-7,8,9,10-tetrahydroimidazo[1,2-h][1,7]-naphthyridine

Participants

Reaction Steps

A mixture of 0.8 g of (8S,9R)-2,3-dimethyl-8-benzyl-8-hydroxy-9-phenyl-7,8,9,10-tetrahydroimidazo-[1,2-h][1,7]naphthyridin-7-one suspended in 20 ml of methanol is treated in portions with 3.3 g of sodium borohydride (30 minutes), stirred at room temperature for 20 h and then refluxed for 5 h. It is then concentrated to dryness in vacuo and stirred into a mixture of 20 ml of water and 20 ml of dichloromethane, the mixture is adjusted to pH 8 using dilute hydrochloric acid with cooling, after separating off the aqueous phase this is extracted a further three times with 50 ml of dichloromethane each time, and the organic phases are combined, washed with a little water and concentrated to dryness in vacuo on a rotary evaporator. The residue obtained is purified on silica gel (eluent: dichloromethane/methanol 13/1). 0.3 g of the title compound of melting point 115-22° C. (diisopropyl ether) are obtained.

Provenance & Evidence