Triethylamine → 5-amino-1-isopropyl-3-(3-nitrophenyl)-1H-pyrazole-4-carbonitrile

Participants

Reaction Steps

Compound 25 (5 g, 21.8 mmol), isopropylhydrazine hydrochloride (2.41 g, 21.8 mmol) (purchased from Ryan Scientific) and triethylamine (6.40 mL, 46.0 mmol) were allowed to react in ethanol (145 mL) at room temperature for 1 hr. After concentrating the reaction mixture, it was purified by silica chromatography using a chloroform/methanol solvent system (methanol gradient increased with time from 0-10%). The relevant fractions were concentrated in vacuo to yield a yellow powder (4.65 g, 79% yield): 1H NMR (400 MHz, DMSO) δ 8.59 (s, 1H), 8.24 (m, 2H), 7.78 (t, J=8.2, 1H), 6.82 (br, 2H), 4.53 (hept, J =6.5, 1H), 1.36 (d, J=6.5, 6H). 13C NMR (100 MHz, DMSO) δ 153.04, 148.76, 146.98, 133.97, 132.22, 131.19, 123.80, 120.37, 116.28, 70.74, 48.64, 22.02; [M+H]+ calculated for C13H11N5O2 272.1, found 272.3.

Provenance & Evidence