1-(2-Methoxyphenyl)piperazine → 4-(2-Methoxyphenyl)piperazine-1-carbaldehyde

Participants

Reaction Steps

DMF was added to a stirred suspension of 4-benzoyloxy-5-methoxy-2-nitro benzoic acid (6) (0.500 mg, 1.65 mmol) and thionyl chloride (3 ml) in dry benzene (30 ml) and the stirring was continued for 6 h. The benzene was evaporated in vacuum and the resultant oil dissolved in dry THF (50 ml) and added drop wise over a period of 1 h to a stirred suspension of 1-(2-methoxyphenyl)piperazine (316 mg 15.6 mmol) triethyl amine (5 ml). After the completion of addition, the reaction mixture was brought to ambient temperature and stirred for an additional hour. The THF was evaporated in vacuum and the aqueous layer was washed with ethyl acetate. The aqueous phase was then adjusted to pH 3 using 6 N HCl and extracted with ethyl acetate and washed with brine, dried over Na2SO4 and evaporated in vacuum to afford the crude product of 2-amino-4-benzyloxy)-5-methoxyphenyl][4-(2-methoxyphenyl)piperazino]methanone (7a) in 93% yield (670 mg, 85% yield). 1H NMR (CDCl3) δ 3.20-3.30 (m, 4H), 3.40-3.55 (m, 4H), 3.85 (S, 3H), 3.95 (s, 3H), 5.20 (s, 2H), 6.80-7.00 (m, 5H), 7.30-7.50 (m, 5H), 7.70 (s, 1H); FABMS: 477 (M+H)+.

Provenance & Evidence