反应详情

To a solution of 205 (340 mg, 1.6 mmol), N,N'-bis-tert-butoxycarbonylthiourea (442 mg, 1.6 mmol, prepared according to literature procedure: Synthetic Commun.1993, 23, 1443.), and Et3N (292 mL, 3.36 mmol) in DMF (4 mL) at 0° C. was added HgCl2 (478 mg, 1.76 mmol) and the mixture was allowed to warm to rt overnight, stirring a total of 20 h. The crude product was isolated in the same manner as described in Example 201 and the was chromatographed on silica gel (5% ethyl acetate/dichloromethane) to afford bis-Boc-guanidine 206 (229 mg, 31%) as a pale orange solid: 1H NMR (300 MHz, CDCl3) d 1.49 (s, 9H), 1.54 and 1.56 (2s, 18H), 4.48 (br s, 2H, NOE observed for C-4 NH2 and C-3 H), 6.73 (d, 1H, J=8.4), 7.68 (dd, 1H, J=1.6, 8.4), 7.86 (s, 1H), 9.96 (s, 1H), 11.64 (s, 1H).

1. customThe crude product was isolated in the same manner
2. customthe was chromatographed on silica gel (5% ethyl acetate/dichloromethane)