Oxalyl chloride → N,N'-Bis(tert-butyl)-N,N'-diphenylformamidinium chloride

Participants

Reaction Steps

Oxalyl chloride (0.42 mL, 5.0 mmol) was added dropwise to a solution of 2a (0.582 g, 3.28 mmol) in toluene (10 mL) at −78° C. The reaction mixture was stirred for 2 h at room temperature. After evaporation of all the volatiles by vacuum, CH2Cl2 (10 mL) was added. 3a (0.778 g, 3.50 mmol) was added to the reaction solution at −78° C., and the reaction mixture was slowly warmed to room temperature for 30 min. After stirring for 3 h at room temperature, the reaction solution was concentrated to 2 mL. The solution was dropped to a rapidly stirred hexanes (10 mL). The precipitated solid was collected and was washed with hexane (10 mL×2) to give 4a (1.028 g, 90.8%) as a white solid. 1H NMR (300 MHz, CDCl3) δ 8.90 (s, 1H), 7.11-6.78 (m, 10H), 1.56 (s, 18H); 13C NMR (75 MHz, CDCl3) δ 153.8, 136.1, 130.3, 128.9, 66.2, 29.7. HRMS-ESI (m/z): [M]+ calcd for C21H29ClN2, 309.2325. found, 309.2322.

Provenance & Evidence