1613191-74-4

1613191-73-3

Step 2: Synthesis of allyl 3,5-diamino-1H-pyrazole-4-carboxylate Allyl 3-amino-4,4,4-trichloro-2-cyano-but-2-enoate (619 g, 2.297 mol) was suspended in DMF (2.476 L) at 0 °C, and KOAc (676.3 g, 6.891 mol) and hydrazine hydrate (172.5 g, 167.6 mL, 3.446 mol) were added sequentially, with the hydrazine hydrate needing to be added in a 15 min Hydrazine hydrate was added slowly over 15 minutes. The reaction mixture was stirred at ambient temperature for 2 h. Complete consumption of the feedstock was confirmed by XH NMR. Subsequently, the reaction mixture was heated to 110 °C and kept overnight, cooled to ambient temperature and continued stirring for 48 hours. Upon completion of the reaction, the mixture was filtered through a sintered glass funnel to remove precipitated solids and the filtrate was concentrated under reduced pressure to give a thick liquid. After addition of DCM (~2 L), the mixture was filtered again to remove additional solid precipitation. The filtrate was purified by chromatography on a 1 kg silica gel column using a DCM/MeOH gradient elution. The target fraction was collected and the solvent was removed under reduced pressure to give an orange solid. This solid was suspended in acetonitrile and heated to about 70 °C until completely dissolved, then cooled to ambient temperature and further cooled to 2 °C. The solid was then purified by column chromatography using a DCM/MeOH gradient. The precipitate precipitated was collected by vacuum filtration, washed with cooled MeCN (ca. 50 mL) and dried in a vacuum oven to constant weight to afford the title compound allyl 3,5-diamino-1H-pyrazole-4-carboxylate as an off-white powder (171.2 g, 41% yield). LC-MS (M + H) + 183.0; 1H NMR (500 MHz, DMSO-d6) δ 10.60 (br s, 1H), 5.95-6.05 (m, 1H), 5.17-5.40 (m, 6H), 4.60 (d, 2H).