4-Chloromethyl-5-((Z)-2-tritylthioethen-1-yl)thiazole (5.57 g) was suspended in 100 ml of THF and 30 ml of ethylene glycol, 1.5 g of sodium hydride was added to the suspension, and the mixture was stirred at 50° C. for 37 hr. Brine was added to the reaction solution, and the mixture was extracted twice with ethyl acetate. The organic layers were combined, were washed twice with brine, were dried over anhydrous magnesium sulfate, were filtered, and were concentrated under the reduced pressure. The residue was purified by column chromatography on silica gel (ethyl acetate) to give 4.87 g of the title compound.
