Triethylamine → 4,5,7,8-Tetrahydro-thieno[2,3-d]azepine-6-carboxylic acid ethyl ester

Participants

Reaction Steps

To a solution of 5,6,7,8-tetrahydro-4H-thieno[2,3-d]azepine (951 mg, 5.03 mmol) in THF (20 ml) at 0° C. was added triethylamine (1526 mg, 15.09 mmol) and ethyl chloroformate (573 mg, 5.3 mmol). The reaction mixture was warmed to ambient temperature for 4 hours and then diluted with water (100 ml) and extracted with EtOAc (3×75 ml). The combined organic phases were washed with brine (100 ml), dried (MgSO4), and concentrated in vacuo to give the crude product as an oil. Purification by flash chromatography (gradient elution: 0 to 40% EtOAc in hexane) afforded the subtitled compound as an oil; yield 77%. 1H NMR (300 MHz, CDCl3) 6.96 (d, J=5 Hz, 1 H), 6.76 (d, J=5 Hz, 1 H), 4.18 (q, J=7 Hz, 2 H), 3.52-3.78 (m, 4 H), 2.78-3.08 (m, 4 H), 1.28 (t, J=7 Hz, 3 H); MS: ESI (positive): 226 (M+H).

Provenance & Evidence