Methanol → 3-(Methylamino)isoquinoline-6-carboxylic acid

Participants

Reaction Steps

Methyl 3-(methylamino)isoquinoline-6-carboxylate was prepared by a method analogous to that described in Step 3 of Intermediate 21, using 6-bromo-N-methylisoquinolin-3-amine. To the crude material (580 mg, 2.7 mmol) was added water (5 mL), methanol (5 mL), and lithium hydroxide monohydrate (300 mg, 7 mmol). The mixture was stirred at room temperature overnight. The reaction was concentrated and the residue was acidified to pH=5 with 1 N aqueous hydrochloric acid. The resulting residue was dried under vacuum and purified by reversed-phase HPLC to give the title compound (512 mg, 89%) as a white solid. 1H NMR (400 MHz, CD3OD, δ): 8.81 (s, 1H), 8.23 (s, 1H), 7.80 (d, 1H), 7.72 (d, 1H), 6.70 (s, 1H), 2.93 (s, 3H).

Provenance & Evidence