Nitric Acid → HCID 13457930, compound

Participants

Reaction Steps

To a stirred solution of cis-1,3,4,6,7,11b-hexahydro-2-methyl-7-phenyl-2H-pyrazino[2,1-a]isoquinoline dihydrochloride (10.0 g, 0.0285 m) in trifluoroacetic acid (100 ml) maintained at 0° under nitrogen was added dropwise over a period of 30 minutes 90% nitric acid (25 ml). The mixture was stirred for 2 hours, then poured onto ice (1000 ml). Chloroform (200 ml) was added and the mixture basified to pH 11 with 50% NaOH. The layers were separated and the aqueous phase extracted with chloroform (2×200 ml). The combined chloroform extracts were washed with water (500 ml), dried over MgSO4, and evaporated to a yellow oil, 9.8 g. This was dissolved in methanol (200 ml), filtered, and the filtrate acidified with HCl gas. A white solid crystallized upon standing which was collected by filtration. This solid was recrystallized twice from methanol (200 ml) and water (10 ml) and vacuum dried at 95° for 24 hours to give 4.04 g of cis-1,3,4,6,7,11b-hexahydro-2-methyl-7-(4-nitrophenyl)-2H-pyrazino[2,1-a]isoquinoline dihydrochloride, m.p. 251°-252°.

Provenance & Evidence