Boron tribromide → HCID 178468704, compound

Participants

Reaction Conditions

Reaction Steps

A −78° C. solution of the above-prepared 5-(4-methoxymethyl-2-phenyl-thiazol-5-yl)-2H-pyrazole-3-carboxylic acid ethyl ester (1.5 g, 4.37 mmole, 1.0 eq) in dry CH2Cl2 (20 ml) was treated with a solution of 1.0M BBr3 in CH2Cl2 (5.24 ml, 5.24 mmole, 1.2 eq) and the mixture stirred at −78° C. for 45 minutes, then allowed to warm to room temperature and stirred for one hour. The reaction mixture was quenched by adding saturated NaHCO3, stirred for 30 minutes then extracted twice with CH2Cl2. The organic phase was washed with brine, dried over anhydrous sodium sulfate and concentrated in vacuo to give a yellow solid. Silica gel chromatography using a gradient elution of (3:2)-(1:1) hexanes-ethyl acetate provided 610 mg (36%) of the title compound as an off white solid. 1H NMR (CDCl3): δ 1.4 (t, 3H), 4.4 (q, 2H), 4.9 (s, 2H), 7.2 (s, 1H), 7.4 (m, 3H), 7.95 (m, 2H), 11.1 (bs, 1H).

Provenance & Evidence