Trimethyl orthoformate → 2-(4-Chloro-phenyl)-4-(2,2-dimethoxy-ethyl)-thiazole-5-carboxylic acid methyl ester

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Reaction Steps

Mix 2-(4-chloro-phenyl)-4-(2-oxo-ethyl)-thiazole-5-carboxylic acid methyl ester (96.4 g, 308 mmol), Dowex™ 50×8 ion exchange resin (33.3 g), and trimethyl orthoformate (147 mL) in MeOH (670 mL). Stir the slurry overnight at room temperature. Filter through a plug of diatomaceous earth and rinse with MeOH (3×300 mL). Stir the filtrate at 0° C. for 2 h and then concentrate to a volume of approximately 250 mL. Collect the solid by filtration, rinse with cold MeOH, and dry overnight at room temperature to obtain 88.2 g (84%) of the titled compound. ES/MS m/z (35Cl) 342.0 [M+1]+.

Provenance & Evidence