3,5‐Dimethyl‐1‐pyrazolylformaminidium Nitrate

Abstract

[38184-47-3] C6H10N4·HNO3 (MW 201.18) InChI = 1S/C6H10N4.HNO3/c1-4-3-5(2)10(9-4)6(7)8;2-1(3)4/h3H,1-2H3,(H3,7,8);(H,2,3,4) InChIKey = AGYXIUAGBLMBGV-UHFFFAOYSA-N (guanylating reagent for amines and hydrazines1; ligand for transition metals2,3) Alternative Names: 1-amidino-3,5-dimethylpyrazole nitrate, 3,5-dimethylpyrazole-1-carboxamidine nitrate. Physical Data: mp 166–168 °C (dec.) (recrystallized ethanol); picrate has mp 206–208.5 °C (recrystallized ethanol); free base has mp 70–71 °C (recrystallized benzene). Solubility: insol cold alcohol, ether; sol cold water, hot water, hot alcohol; it gives on treatment with ammoniacal silver nitrate solution a white silver salt, which is also insol excess ammonia; hydrochloride salt is sol water, alcohol; the free base is sol water, alcohol; very sol ether, and sol benzene. Form Supplied in: colorless prisms; picrate crystallizes in microscopic needles; free base crystallizes as white needles of characteristic odor. Preparative Method: aminoguanidine nitrate (0.5 mol) is added portionwise over a period of 1.75 h to a refluxing solution of acetylacetone (0.5 mol) in 50% aqueous ethanol (140 mL) and the resultant solution is heated under reflux for 2.25 h. The solution is allowed to stand overnight and the resultant crystals are collected, washed with ether, and dried in vacuo. Further crops are obtained by dilution of the filtrate with ether. Recrystallization of the combined crude substances (78.3 g) from ethanol gives 64.6 g (65%) of product. Handling, Storage, and Precautions: store in a tightly sealed container, in a dry and well-ventilated place. Causes skin irritation and serious eye irritation. Avoid inhalation of dust and use in a fume hood.