p-Toluenesulfonic acid monohydrate → p-Toluenesulfonic acid

Participants

Reaction Steps

A solution of the product of Example 82C (9 mg, 0.027 mmol) in methanol (10 mL) was treated with PtO2 (10 mg). The reaction flask was evacuated and purged with nitrogen (4 cycles), then with hydrogen (5 cycles), and the suspension was stirred at room temperature under hydrogen (1 atm) for 40 hours. The flask was evacuated and purged with nitrogen (5 cycles) and the mixture was filtered through a pad of diatomaceous earth with methanol (5 mL) rinse. The filtrate was concentrated under vacuum and the residue was taken up in ethyl acetate (1 mL). A solution of p-toluenesulfonic acid monohydrate (5.5 mg, 0.029 mmol) in ethyl acetate (0.5 mL) was added, and the mixture was stirred for 30 minutes, then concentrated under vacuum. The residual solid was triturated with ethyl acetate (0.2 mL) and dried under vacuum to provide the title compound as the p-toluenesulfonate salt: 1H NMR (300 MHz, methanol-d4) δ ppm 1.72-1.87 (m, 2H), 1.97-2.09 (m, 2H), 2.14 (s, 2H), 2.15 (s, 1H), 2.19-2.31 (m, 1H), 2.35 (s, 3H), 2.41-2.71 (m, 2H), 2.81 (s, 1H), 2.96 (s, 2H), 2.99-3.15 (m, 3H), 3.37-3.53 (m, 2H), 3.57-3.69 (m, 1H), 4.15-4.29 (m, 2H), 4.29-4.38 (m, J=4.8 Hz, 1H), 5.02-5.13 (m, 1H), 7.08-7.26 (m, 4H), 7.45 (t, J=7.7 Hz, 1H), 7.53 (d, J=7.9 Hz, 1H), 7.64 (d, J=8.3 Hz, 2H); MS (DCI) m/z 337 (M+H)+.

Provenance & Evidence