Hydrochloric Acid → HCID 2807828, compound

Participants

Reaction Steps

LiBH4 in THF (2M, 15 ml, 0.03 mole) was added dropwise to a stirred solution of ethyl 1-methyl-5-(trifluoromethyl)-1H-pyrazole-4-carboxylate (3.32 g, 0.015 mole) in THF (40 ml) at room temperature under nitrogen. The solution was then stirred under reflux for 18 hrs. After cooling, the cloudy solution was evaporated at room temperature to give an oil. Water was added (heavy ppt. of white solid) and the mixture chilled and treated cautiously with hydrochloric acid (2M) to pH 2 (no solid remaining, to give an oil). The mixture was neutralised with sodium carbonate and the mixture extracted with diethyl ether (3×20 ml). The organic layer was separated and back-washed with brine (3×30 ml). The organic layer was separated, dried (Na2SO4), filtered and evaporated to give an oil. Yield 3 g. An aliquot (150 mg) was dissolved in dichloromethane and purified using an ISCO Companion (4 g silica col. CH2Cl2 to CH2Cl2:ethyl acetate 9:1). The appropriate fractions were combined and evaporated to give an oil, 72 mg. 1H NMR (400 MHz, CDCl3) δ 7.54 (s, 1H) 4.69, 4.48 (d, 2H) 4.00 (s, 3H) 1.70, 1.68, 1.67 (t, 1H). MS (ESI) m/z 181 (M+H)+. LC-MS m/z 181 (M+H) GC-MS FID 100% Cl+ 181 (M+H)+. TLC CH2Cl2:ethyl acetate 9:1 0.25 UV−ve DNPH+ve.

Provenance & Evidence