反应详情

77 g of 2,5-dihydroxybenzoic acid and 78.5 g of p-chloronitrobenzene were dissolved in 300 ml of dimethyl sulphoxide under a nitrogen atmosphere, and 40 g of sodium hydroxide and 225 ml of benzene were added to the resulting solution. The mixture was then distilled under reflux at 90° to 95° C on a water separator until no more water was separated off (about 2 hours). The benzene was distilled off in a water jet vacuum, the residue poured into 2.5 liters of water, the mixture acidified with concentrated hydrochloric acid while stirring vigorously, the crude, pale brown 5-(4-nitrophenoxy)-salicylic acid which was precipitated was filtered off under suction and washed acid free with water. Drying in vacuo at 80° C gave 126 g (92% of the theoretical yield) of 5-(4-nitrophenoxy)-salicylic acid, recrystallised from methanol (and active carbon, optionally with a little water added) 120 g (87% of the theoretical) of yellow crystals melting at 193° to 194° C.

1. distillationThe mixture was then distilled
2. temperatureunder reflux at 90° to 95° C on a water separator until no more water
3. customwas separated off (about 2 hours)
4. distillationThe benzene was distilled off in a water jet vacuum
5. additionthe residue poured into 2.5 liters of water
6. customthe crude, pale brown 5-(4-nitrophenoxy)-salicylic acid which was precipitated
7. filtrationwas filtered off under suction
8. washwashed acid free with water
9. customDrying in vacuo at 80° C
10. customgave 126 g (92% of the