Hydrochloric Acid → 4,5-Dihydro-imidazo-[1,2-a]-quinoxaline-2-methanol

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Reaction Steps

2.8 g of lithium borohydride were added to a solution of 10 g of ethyl imidazo-[1,2-a]-quinoxaline-2-carboxylate of Step B in 230 ml of anhydrous tetrahydrofuran and the mixture was stirred at reflux for 18 hours. The resulting yellow suspension was poured into dilute hydrochloric acid to react with the boron complex and the mixture was made alkaline with sodium carbonate addition. The mixture was extracted with ethyl acetate and the organic phase was evaporated to dryness to obtain 5.9 g of 4,5-dihydro-imidazo-[1,2-a]-quinoxaline-2-methanol in the form of a buff crystalline solid melting at 172°-174° C. after crystallization from ethyl acetate to obtain a white crystalline solid.

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