Sodium borohydride → Ethyl {4-[2-(allyloxy)-4-methylphenyl]-2-methyl-5,6,7,8-tetrahydro[1]benzothieno[2,3-b]pyridin-3-yl}(hydroxy)acetate

Participants

Reaction Steps

To a stirred solution of ethyl {4-[2-(allyloxy)-4-methylphenyl]-2-methyl-5,6,7,8-tetrahydro[1]benzothieno[2,3-b]pyridin-3-yl}(oxo)acetate hydrochloride salt (Step 6, 1.1 g, 2.56 mmol) in ethanol (20 mL) was added sodium borohydride (145 mg, 3.84 mmol), and the reaction was stirred at room temperature for 5 minutes. The reaction was concentrated in vacuo, and the residue was partitioned between ethyl acetate (20 mL) and hydrochloric acid (aqueous, 1N, 30 mL). The organic layer was separated, washed with brine (10 mL), dried over MgSO4, filtered and concentrated in vacuo to give a mixture of diastereoisomers of the title compound as a pale orange gum, 1.1 g, in a 91% yield. LCMS (2 min acidic) 1.53 min 52-81% pure by UV, ES+/AP+ 452. 1HNMR (400 MHz, CDCl3 δ ppm 1.17-1.21 (m, 3H), 1.53-1.64 (m, 2H), 1.71-1.87 (m, 4H), 2.43 (s, 3H), 2.63 (s, 3H), 2.81 (t, 2H), 4.08-4.22 (m, 2H), 4.47-4.51 (m, 2H), 5.08-5.17 (m, 2H), 5.18 (s, 1H), 5.86 (m, 1H), 6.79 (s, 1H), 6.81-6.85 (m, 1H), 7.02 (d, 1H).

Provenance & Evidence