Acetic Acid → HCID 57404717, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of hydroxylamine hydrochloride (2.0 g, 29 mmol) in methanol (10 mL) was heated at 90° C. under a dry nitrogen atmosphere until homogeneous. To this heated solution was added a solution of potassium hydroxide (2.85 g, 50.8 mmol) in methanol (6 mL). A precipitate formed on mixing. After heating at 90° C. for 30 minutes, the mixture was cooled to rt and the solids were allowed to settle. The resulting solution was assumed to contain 1.7 M hydroxylamine.potassium salt and was carefully removed by syringe to exclude solids. An aliquot of the above solution (1.95 mL, 3.31 mmol) was added to a solution of methyl 2-{[1-(tert-butoxycarbonyl)-4-methylpiperidin-4-yl]carbonyl}-1,2,3,4-tetrahydroisoquinoline-6-carboxylate (138 mg, 0.331 mmol) in methanol (0.5 mL) and DMF (0.5 mL). After stirring for 3 h at rt, excess reagent was quenched by the addition of acetic acid (0.188 mL, 3.31 mmol). The mixture was concentrated to dryness and the residue was twice co-evaporated with toluene. The crude product was purified by preparative HPLC to afford tert-butyl 4-{[6-(hydroxycarbamoyl)-3,4-dihydroisoquinolin-2(1H)-yl]carbonyl}-4-methylpiperidine-1-carboxylate (103 mg, 74.5%). LC-MS: (FA) ES+ 418; 1H NMR (400 MHz, DMSO) δ 11.03 (s, 1H), 9.00 (s, 1H), 7.59-7.52 (m, 2H), 7.28 (d, J=8.0 Hz, 1H), 4.71 (s, 2H), 3.79 (t, J=5.8 Hz, 2H), 3.53-3.44 (m, 2H), 3.15-3.03 (m, 2H), 2.83 (t, J=5.4 Hz, 2H), 2.06-1.96 (m, 2H), 1.47-1.39 (m, 2H), 1.37 (s, 9H), 1.24 (s, 3H).

Provenance & Evidence