反应详情

Compound 2 (0.438 g, 1.48 mmol) was dissolved in MeOH (7.00 mL), and successively treated with N,N′-bis-tert-butoxycarbonyl-1H-pyrazole carboxamidine (0.412 g, 1.33 mmol) and i-Pr2NEt (0.380 g, 2.95 mmol) at ambient temperature. The resulting mixture was stirred 3 h then concentrated and purified by chromatography on SiO2 (A: hexanes; B: EtOAc; 0-100% B over 19.2 min; 40 mL/min; 40 g column) to obtain the product as a white foam (0.61 g, 82%). 1H NMR (300 MHz, CDCl3) δ 8.5 (t, 1H), 7.5 (d, 1H), 7.2 (dd, 1H), 6.85 (d, 1H), 4.52 (d, 2H), 4.18 (t, 2H), 3.9 (t, 2H), 2.1 (m, 2H), 1.52 (s, 9H), 1.47 s (s, 9H).

1. concentrationthen concentrated
2. custompurified by chromatography on SiO2 (A: hexanes
3. wait0-100% B over 19.2 min