Sodium Azide → 1,1-Dimethylethyl (2S)-2-[6-(2-azidoacetyl)-1H-benzimidazol-2-yl]-1-pyrrolidinecarboxylate

Participants

Reaction Conditions

Reaction Steps

Sodium azide (1.79 g, 27.48 mmol) was added in one portion to a solution of J.30 (S)-tert-butyl 2-(6-(2-chloroacetyl)-1H-benzo[d]imidazol-2-yl)pyrrolidine-1-carboxylate (10.0 g, 27.48 mmol) in acetonitrile (200 mL) and stirred at 60° C. for 16 h. The reaction mixture was concentrated to ⅕ volume, diluted with ethyl acetate, and washed with water and brine prior to being dried (Na2SO4). Concentration gave J.31 (S)-tert-butyl 2-(6-(2-azidoacetyl)-1H-benzo[d]imidazol-2-yl)pyrrolidine-1-carboxylate 6.8 g (48%) as a golden orange foam. 1H NMR (500 MHz, DMSO-d6) δ: 8.22/8.03 (s, 1H), 7.80-7.75 (m, 1H), 7.65/7.56 (d, J=8.5 Hz, 1H), 4.99-4.93 (m, 3H), 3.60 (br. s, 1H), 3.46-3.41 (m, 1H), 2.38-2.27 (m, 1H), 2.01-1.89 (m, 3H), 1.40/1.06 (s, 9H). LC (Cond.-D2): 1.97 min; LC/MS: Anal. Calcd. for [M+H]+ C18H23N6O3: 371.19; found: 371.32. HRMS: Anal. Calcd. for [M+H]+ C18H23N6O3: 371.1832; found: 371.1825.

Provenance & Evidence