p-Nitroacetophenone → 2-Bromo-4'-nitroacetophenone

Participants

Reaction Conditions

Reaction Steps

To 82.5 g. of p-nitroacetophenone in 200 ml. of glacial acetic acid at 20°-25° C. is added 80 g. of bromine dropwise over 30 minutes. The resulting solution is cooled to 8° C. A precipitate forms during cooling which is filtered, washed and partially dried. 109 g. of wet alpha-bromo-p-nitroacetophenone is obtained. It is added to 109 g. of Na2S2O3.5H2O in 400 ml. of 70% methanol. The mixture is stirred, warmed to 60° C. and allowed to stand overnight. The mixture is cooled and a solid precipitates which is filtered and dried. The resulting cake is added to 600 ml. water, 600 ml. acetic acid and 300 ml. concentrated aqueous HCl. This mixture is stirred at refluxing temperature for 6 hours. An orange-red precipitate forms which is recovered and dried. NMR analysis indicates that the product is 2,5-di(p-nitrophenyl)dithiin having the structure: ##STR9##

Provenance & Evidence