Formaldehyde → N-(2-Methyl-1,2,3,4-tetrahydroisoquinoline-7-sulphonyl)-3-cyano-(S)-phenylalanine ethyl ester

Participants

Reaction Steps

Aqueous formaldehyde solution (370 w/v, 3.15 ml, 42 mmol) was added to a stirred solution of N-(1,2,3,4-tetrahydroisoquinoline-7-sulphonyl)-3-cyano-(S)-phenylalanine ethyl ester (Preparation 23; 3.5 g, 8.5 mmol) in dichloromethane (100 ml). After 1 hour, sodium triacetoxyborohydride (566 mg, 2.67 mmol) was added and stirring continued for 2 hours. The reaction mixture was then washed with saturated aqueous sodium bicarbonate solution, dried (MgSO4) and evaporated under reduced pressure to furnish the title compound (3.6 g) as a white foam. Rf 0.83 (SS 3). m/e 428 (M+H)+.

Provenance & Evidence