3-Amino-4-hydroxybenzoic acid → 2-(4-Carbomethoxyphenyl)-5-carboxybenzoxazole
Reaktionsgleichung
[CH3:1][O:2][C:3](=[O:14])[C:4]1[CH:9]=[CH:8][C:7]([C:10](Cl)(Cl)Cl)=[CH:6][CH:5]=1.[NH2:15][C:16]1[CH:17]=[C:18]([CH:22]=[CH:23][C:24]=1[OH:25])[C:19]([OH:21])=[O:20]>>[C:3]([C:4]1[CH:9]=[CH:8][C:7]([C:10]2[O:25][C:24]3[CH:23]=[CH:22][C:18]([C:19]([OH:21])=[O:20])=[CH:17][C:16]=3[N:15]=2)=[CH:6][CH:5]=1)([O:2][CH3:1])=[O:14]Komponenten
3
Reaktionsbedingungen
- Temperatur
- 200 °C
Versuchsvorschrift
In the apparatus described in Example 1, 12.7 g of 4-trichloromethylbenzoic acid methyl ester (0.05 mol) and 7.5 g of 3-amino-4-hydroxybenzoic acid (0.05 mol) were mixed and heated for 6 hours at 200° C. The reaction product after grinding in a mortar was extracted twice with 100 ml of CHCl3 and then, after drying, twice with 100 ml of water. 9.2 g of raw product remained, melting at 275° to 284° C (62% of the theory). After two recrystallizations with dimethyl formamide plus active charcoal and dimethylsulfoxide, the melting point was 291° to 293° C.