Lithium Hydroxide → HCID 67253411, compound

Participants

Reaction Steps

A suspension of ethyl 5-tert-butyl-1-(quinolin-6-yl)-1H-pyrazole-3-carboxylate hydrochloride (32 g, 0.089 mol) in THF (300 mL) was treated with aqueous LiOH (2 N, 100 mL, 0.20 mmol) and the resultant mixture was heated to 40° C. for 3 hours. The reaction was concentrated under reduced pressure and the remaining aqueous layer was washed with EtOAc. The aqueous phase was acidified to pH 3 and the resultant precipitate was collected by filtration, washed with cold ether and dried in vacuo to provide 5-tert-butyl-1-(quinolin-6-yl)-1H-pyrazole-3-carboxylic acid (21 g, 71% yield). 1H-NMR (400 MHz, DMSO-d6) δ 9.03 (m, 1H), 8.50 (d, J=8.7 Hz, 1H), 8.20 (d, J=2.4 Hz, 1H), 8.15 (d, J=8.8 Hz, 1H), 7.79 (dd, J=8.7 Hz, 2.4 Hz, 1H), 7.67 (dd, J=8.4, 4.4 Hz, 1H), 6.68 (s, 1H), 1.17 (s, 9H); MS (ESI) m/z: 296.3 (M+H+).

Provenance & Evidence