Triethylamine → tert-butyl N-({[(tert-butoxy)carbonyl]amino}methanimidoyl)carbamate

Participants

Reaction Conditions

Reaction Steps

To a solution of amine 228 (126 mg, 0.42 mmol), N,N'-bis-tert-butoxycarbonylthiourea (127 mg, 0.46 mmol), and triethylamine (123 μL, 0.88 mmol) in DMF (4 mL) at 0° C. was added HgCl2 (125 mg, 0.46 mmol). The mixture was stirred at 0° C. for 30 min and at room temperature for 1.5 h. The reaction was diluted with ethyl acetate and filtered through celite. The solvent was evaporated and the residue was partitioned between ethyl acetate and water. The organic phase was washed with saturated NaCl, dried (MgSO4), filtered and the solvent was evaporated. The crude product was purified on silica gel (2/1, 1/1-hexane/ethyl acetate) to afford bis-Boc-guanidine 251 (155 mg, 69%) as a solid: 1H NMR (CDCl3) δ11.40 (s, 1H), 8.66 (d, 1H, J=7.9), 6.8 (s, 1H), 6.22 (d, 1H, J=8.9), 4.43-4.34 (m, 1H), 4.19-4.08 (m, 1H), 4.03 (m, 1H), 3.76 (s, 3H), 3.35 (m, 1H), 2.79 (dd, 1H, J=5.4, 17.7), 2.47-2.36 (m, 1H), 1.92 (s, 3H), 1.50, 1.49 (2 s, 18H), 0.89 (m, 6H).

Provenance & Evidence