Hydrochloric Acid → HCID 178498633, compound

Participants

Reaction Steps

Place trimethylsilyl-diazomethane (2 M in THF) (25 mL, 50 mmol) in THF (50 mL). Cool the reaction to −78° C. and add lithium diisopropylamide (2 M in THF) (25 mL, 50 mmol) over 30 min. Add methyl propiolate (4.45 mL, 50 mmol) and stir at −78° C. for 2 hours. Warm to room temperature and stir for 18 hours. Add ethyl acetate, water, and 1 N HCl. Separate organic layer and extract aqueous with ethyl acetate (2×25 mL). Combine organic extracts, dry over Mg2SO4, filter, and concentrate under reduced pressure. Subject residue to silica gel chromatography eluting with 0-60% EtOAc:hexane to yield 3.59 g (36%) of 5-trimethylsilanyl-2H-pyrazole-3-carboxylic acid methyl ester.

Provenance & Evidence