Ammonia → 2-Methyl-7-nitro-1,2,3,4-tetrahydroisoquinoline

Participants

Reaction Steps

A solution of 4.00 g (18.7 mmol) of 7-nitroisoquinoline in 10 ml of formic acid and 17 ml of 38% aqueous formaldehyde was heated at reflux for 1 h. The reaction mixture was cooled, poured onto ice and basified with aqueous ammonia. The gummy residue which precipitated was extracted twice with methylene chloride. The dried (magnesium sulfate) organic phase was concentrated to give crude 7-nitro-2-methyl-1,2,3,4-tetrahydroisoquinoline as a thick oil. This oil was immediately taken up in ethanol (50 ml) and a solution of hydrochloric acid in ethanol was added until the solution was distinctly acidic to litmus. Ether was added to induce precipitation and the resulting solid was collected to give 3.99 g (93%) of the title compound as a yellow solid, m.p. 236-8° C. (dec).

Provenance & Evidence