Tetrahydrofuran → Methyl 4-amino-1,3-thiazole-5-carboxylate

Participants

Reaction Steps

To a solution of 37.6 g of 4-amino-2-methanesulfonylthiazole-5-carboxylic acid methyl ester in 1 liter of a methanol:THF=1:1 mixed solvent at room temperature there was added 15 g of sodium borohydride in small portions over a period of 10 hours. The reaction mixture was stirred at room temperature for 40 hours, and then poured into a mixture of 6 liters of ethyl acetate and 3 liters of water. The organic layer was washed with 3 liters of water and 3 liters of saturated brine, and the aqueous layer was extracted again with ethyl acetate. The organic layers were combined and dried over anhydrous magnesium sulfate. The desiccating agent was filtered off and the filtrate was concentrated under reduced pressure. The residue was purified by silica gel column chromatography (ethyl acetate-heptane) to give the title compound (15.3 g) as a light yellow solid.

Provenance & Evidence