1-(2-Methoxyphenyl)piperazine → 1-(2-methoxy-5-nitrophenyl)piperazine

Participants

Reaction Steps

A solution of 5M sulphuric acid (114 ml) was added over 0.3 h to 1-(2-methoxyphenyl)piperazine (110 g) at 0° C. with stirring. To the ice-cooled stirred slurry was then added, over 1.75 h, concentrated sulphuric acid (560 ml) and the temperature was maintained for a further 1.5 h. Potassium nitrate (71.5 g) was then added portionwise over 1.5 h to the stirred, cold, viscous mixture which was then left to stand for 18 h. The solution was poured onto ice (2 Kg) and the resulting cooled mixture brought to pH 12 by the addition of 40% sodium hydroxide solution. The oily mixture was extracted with ethyl acetate (2×2L) and the combined organic extracts were washed with water (3L), dried (Na2SO4), concentrated to a residue which was stirred with diethyl ether (700 ml) to give the title compound (D1) as a yellow solid, m.p. 84-87° C. (95 g, 70%). MH+238.

Provenance & Evidence