Borane;2-methylpropan-2-amine → ethyl 5,6-dihydro-4H-thieno[2,3-c]azepine-7(8H)-carboxylate

Participants

Reaction Steps

Solid borane-t-butylamine pellets (2.77 g, 31.84 mmol) were crushed and suspended in methylene chloride (300 mL) at 0° C. Solid aluminum trichloride (2.12 g, 15.92 mmol) was added and the mixture was stirred for 1 hour. Compound 1043 (1.27 g, 5.31 mmol) was added slowly and the reaction mixture allowed to warm to room temperature overnight. The reaction was quenched by addition of ethanol (50 mL) then saturated ammonium chloride (100 mL). The mixture was brought to a neutral pH with saturated sodium bicarbonate, extracted with ethyl acetate (3×100 mL), and concentrated to give ethyl 5,6-dihydro-4H-thieno[2,3-c]azepine-7(8H)-carboxylate (Compound 1044) as a tan oil; 1H NMR (300 MHz, CDCl3): δ 6.95-6.85 (m, 1H), 6.70 (d, J=4.7 Hz, 1H), 4.49 (s, 2H), 4.18-4.00 (m, 2H), 3.66-3.58 (m, 2H), 2.77 (t, J=5.7 Hz, 2H), 1.62 (qn, J=6.0 Hz, 2H) and 1.24-1.08 (m, 3H).

Provenance & Evidence