(4-Methoxyphenyl)boronic acid → Ethyl 2-(4-methoxyphenyl)thiazole-4-carboxylate

Participants

Reaction Conditions

Reaction Steps

2-Bromo-thiazole-4-carboxylic acid ethyl ester (1.00 mmol, 236 mg), 4-methoxyphenylboronic acid (1.50 mmol, 228 mg), Pd2(DBA)3 (0.020 mmol, 18 mg), S-Phos (0.060 mmol, 25 mg) and potassium phosphate tribasic monohydrate (1.5 mmol, 0.35 g) were loaded into a Schlenk tube containing a stir bar. The Schlenk tube was capped with a rubber septum, evacuated and refilled with nitrogen. Toluene (2 mL) was added through the septum via a syringe and the Schlenk tube was sealed with a Teflon screw cap under a flow of nitrogen, and put into an oil bath at 100° C. The reaction was allowed to stir at 100° C. for 15 hours, then the reaction mixture was cooled to room temperature and filtered through celite. The filtrate was concentrated in vacuo and the resultant crude residue was purified using column chromatography on silica gel (eluent: Hexane/EtOAc (4:1)) to provide 2-(4-Methoxy-phenyl)-thiazole-4-carboxylic acid ethyl ester as a yellowish solid.

Provenance & Evidence