Hydrazine → Ethyl 3,5-diamino-1H-pyrazole-4-carboxylate

Participants

Reaction Conditions

Reaction Steps

Hydrazine (2.19 mL, 70 mmol) was added to (Z)-ethyl 3-amino-4,4,4-trichloro-2-cyanobut-2-enoate (15.0 g, 58 mmol) in DMF (50 mL). The reaction mixture was heated to 100° C. for 1 hr, then cooled to room temperature. The DMF was removed in vacuo, then the residue was slurried in a 95:5 mixture of DCM:2M methanolic ammonia solution. The resulting precipitate was filtered off, washed with a 95:5 mixture of DCM:MeOH, and dried under vacuum to afford 5.72 g (58%) of ethyl 3,5-diamino-1H-pyrazole-4-carboxylate as a white solid. 1H NMR (400 MHz, DMSO) δ 10.53 (s, 1H), 5.28 (br, 4H), 4.14 (q, J=7.1, 2H), 1.33-1.15 (t, J=7.1, 3H).

Provenance & Evidence