Water → 1-cyclopentyl-5-(trifluoromethyl)-1H-pyrazole-4-carboxylic acid

HRID 12892Notes

Reaction equation

C([O:3][C:4]([C:6]1[CH:7]=[N:8][N:9]([CH:15]2[CH2:19][CH2:18][CH2:17][CH2:16]2)[C:10]=1[C:11]([F:14])([F:13])[F:12])=[O:5])C.O.[OH-].[Li+]>CO>[CH:15]1([N:9]2[C:10]([C:11]([F:12])([F:13])[F:14])=[C:6]([C:4]([OH:5])=[O:3])[CH:7]=[N:8]2)[CH2:16][CH2:17][CH2:18][CH2:19]1

Participants

Conditions

Temperature: 80 °C

Procedure

Cyclopentyl-5-trifluoromethyl-1H-pyrazole-4-carboxylic acid ethyl ester (0.237 g, 0.858 mmol) was dissolved in methanol (2.0 mL). Water (2.0 mL) and lithium hydroxide (0.027 g, 1.127 mmol) were added and the mixture was heated at 80° C. for 2 hours. After cooling to room temperature, the methanol was removed in vacuo. THF was added to the residue and then removed in vacuo to insure complete removal of the methanol. 6N HCl (0.2 mL) was added to the aqueous residue to pH 2-3 resulting in precipitation of a white solid. The solid was collected by filtration, washed with water and dried under high vacuum at 100° C. to give 1-cyclopentyl-5-trifluoromethyl-1H-pyrazole-4-carboxylic acid (0.134 g, 63%).

Workup

temperatureAfter cooling to room temperature
customthe methanol was removed in vacuo
additionTHF was added to the residue
customremoved in vacuo
customremoval of the methanol
addition6N HCl (0.2 mL) was added to the aqueous residue to pH 2-3
customresulting in precipitation of a white solid
filtrationThe solid was collected by filtration
washwashed with water
customdried under high vacuum at 100° C.

Sources & evidence

ORD record: ord-843018d22511459f8f617515e16915c9
Source dataset: uspto-grants-2010_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07728029B2

Reaction notes

Loading…