反应详情

The 2,3-dihydrobenzofuran-7-carboxylic acid (TCI-US, 0.25 g, 1.4 mmol) was converted to 2,3-dihydrobenzofuran-7-carbonyl chloride with 5 mL of thionyl chloride using the method described in Example 134A. The product of Example 126A (0.20 g, 1.1 mmol), Et3N (0.3 mL, 2.2 mmol) and the freshly prepared 2,3-dihydrobenzofuran-7-carbonyl chloride in 30 mL THF were processed as in Example 134B. Purification of the crude material via recrystallization with 50% hexanes:EtOAc gave the title compound (0.12 g, 0.36 mmol, 34% yield). 1H NMR (300 MHz, CD3OD) δ ppm 2.25 (s, 3H), 2.30 (s, 3H), 3.22 (t, J=8.8 Hz, 2H), 3.31 (s, 3H), 3.81 (t, J=5.3 Hz, 2H), 4.44 (t, J=5.3 Hz, 2H), 4.64 (t, J=8.8 Hz, 2H), 6.86 (t, J=7.5 Hz, 1H), 7.32 (dd, J=7.3, 1.2 Hz, 1H), 7.93 (dd, J=8.0, 0.8 Hz, 1H); MS (DCI/NH3) m/z 333 (M+H)+; Anal. calculated for C17H20N2O3S.0.1H2O: C, 61.09; H, 6.09; N, 8.38. Found: C, 60.99; H, 5.91; N, 8.25.

1. customPurification of the crude material
2. customvia recrystallization with 50% hexanes