Hydrochloric Acid → 2,5-Dimethylquinazolin-4-amine

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Reaction Conditions

Reaction Steps

1. 66.2 g of 2-amino-6-methylbenzonitrile and 22 g of acetonitrile are dissolved in 750 ml of absolute dioxan and the solution is cooled to 5° C. Subsequently, a weak stream of dry hydrogen chloride is introduced for 8 h. at 5° to 7° C. The mixture is stirred at room temperature for a further 15 h. and then again cooled to 5° C. A further 11 g of acetonitrile are added thereto, hydrochloric acid gas is introduced for 8 h. and the mixture is stirred at room temperature for a further 15 h. The suspension is subsequently evaporated at 30° C. in a vacuum. The crystalline residue is triturated with 0.71 of water, cooled to 0° to 5° C. neutralized with saturated sodium hydrogen carbonate solution and filtered. The crystals are washed with water and dried in a vacuum. There are obtained 107 g of crude 4-amino-2,5-dimethylquinazoline which still contains inorganic salts. This compound melts at 198°-199° C. after recrystallization from ethanol.

Provenance & Evidence