Ethanol → 3-Methyl-imidazo[2,1-b]thiazole-6-carboxylic acid ethyl ester

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Reaction Steps

To a solution of 6.3 g of phosphorus pentachloride in 120 ml of dry methylene chloride, 5 g of 3-methyl-imidazo-(2,1-b)thiazole-6-carboxylic acid(prepared as described in Example 10) is added and the suspension obtained is refluxed for 3 hours. After vacuum evaporation of the solvent the residue obtained being 3-methyl-imidazo-(2,1-b)thiazole-6-carboxylchloride chlorohydrate is dissolved in 100 ml of abs.ethanol and the solution is refluxed for 4 hours. The solvent is removed and the residue obtained is dissolved in water. The solution obtained is neutralised to pH 7.5 to yield 5 g of 3-methyl-6-carboethoxyimidazo-(2,1-b)thiazole; m.p. 117°-119°.

Provenance & Evidence