Toluene → 2-Amino-5-phenyl-1H-imidazol-3-ium 2,2,2-trifluoroacetate

Participants

Reaction Conditions

Reaction Steps

To a flask charged with ketoguanidine 73 (57.9 mg, 0.153 mmol, 1 equiv) was added toluene (4 mL) and trifluoroacetic acid (120 μL, 1.53 mmol, 10.0 equiv) via syringe and the reaction mixture was heated to 85° C. After 13.5 h, the reaction mixture was allowed to cool to 23° C. and was concentrated under reduced pressure. Water (2 mL) and trifluoroacetic acid (120 μL, 1.53 mmol, 10.0 equiv) were added via syringe to the residue and the resulting mixture was heated to 85° C. After 1.5 h, the reaction mixture was allowed to cool to 23° C. and was concentrated under reduced pressure to give 2-aminoimidazole 74 (34 mg, 82%) as a pale yellow solid. 1H NMR (500 MHz, CD3OD, 21° C.): δ 7.56 (app-d, J=7.2 Hz, 2H), 7.43 (app-t, J=7.7 Hz, 2H), 7.34 (app-tt, J=7.4, 1.2 Hz, 1H), 7.13 (s, 1H). 13C NMR (125.8 MHz, CD3OD, 21° C.): δ 163.1, 149.7, 130.3, 129.7, 129.2, 129.1, 125.6, 109.9, 101.4. FTIR (neat) cm−1: 3182 (br-s), 1682 (br-s), 1204 (s), 1139 (s), 842 (m). HRMS (ESI) (m/z): calc'd for C9H10N3, [M+H]+: 160.0869, found: 160.0867.

Provenance & Evidence