Hydrochloric Acid → HCID 13442313, compound

Participants

Reaction Steps

46.05 g (0.180 mol) of 3,5-dinitrophthalic acid are kept under reflux with 26 g (0.25 mol) of acetic anhydride in 210 ml of toluene for one hour. The mixture is filtered hot and the filtrate is evaporated. The residue is dissolved under reflux together with 27.4 g (0.221 mol) of p-thiocresol and 34.7 g (0.34 mol) of acetic anhydride in 4.6 liters of methylene chloride. This solution is added dropwise, at 20°-27° C., with vigorous stirring, to a solution of 1.9 g (8.5 mmols) of benzyltriethylammonium chloride in 190.4 g of 50% potassium hydroxide solution (1.7 mols). After the dropwise addition (135 minutes), the mixture is stirred thoroughly for 90 minutes and acidified with concentrated hydrochloric acid, with cooling. The mixture is converted to two clear phases with the addition of water and acetone; the organic phase is separated off, dried over sodium sulfate and evaporated. The residue is heated under reflux with 36.7 g of acetic anhydride in 200 ml of toluene, the mixture is filtered hot and the filtrate is evaporated. The above reaction is repeated with the residue, using 21.8 g (0.214 mol) of acetic anhydride, 19.9 g (0.161 mol) of p-thiocresol, 2.4 g of benzyltriethylammonium chloride and 285 g of 30% NaOH solution. After thorough stirring, off, dried over sodium sulfate and evaporated. The residue is converted to the anhydride with 52.1 g of acetic anhydride and 250 ml of toluene. After recrystallisation from methylene chloride/n-pentane, 20.83 g (39% of theory) of 3-(p-methylphenylthio)-5-nitrophthalic anhydride are obtained; melting point: 180°-2° C.

Provenance & Evidence