Potassium Hydroxide → 10-(thiophen-2-ylmethyl)-2,3-dihydroimidazo[2,1-b]quinazolin-5-one

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Reaction Steps

A mixture of 20 g. of N-(2-thienylmethyl)isatoic anhydride, 9 g. of 2-methylmercapto-imidazoline and 1 pellet of potassium hydroxide in about 300 ml. of dioxane is heated at reflux for 5 hours, the solvent then evaporated off and the residue dissolved in methylene chloride. After washing twice with water the solution is extracted 3 times with 1N. hydrochloric solution. Heating on a steam bath avoids precipitation and after filtering hot through celite, sodium bicarbonate solution is added and the resulting precipitate is recovered by filtering, washed with water, dissolved in methylene chloride and the methylene chloride exchanged for diethyl ether. The resulting precipitate is recovered by filtering, washed with diethyl ether and dried under reduced pressure at 40°C. to obtain 10-(2-thienylmethyl)-2,3-dihydro-imidazo[2,1-b]quinazolin-5(10H)-one, m.p. 124°-127°C.

Provenance & Evidence