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, 1 N, 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