Pinacol → 3-[2-Chloro-4-(trifluoromethyl)phenoxy]benzoic acid

To a 300 ml, 3-necked flask equipped with a condenser, stirrer, drying tube and thermometer is charged dimethylsulfoxide (100 ml), anhydrous potassium carbonate (30 g. >0.20 mole), 3,4-dichlorobenzotrifluoride (21.5 g., 0.10 mole), pinacol (10 g.) and 3-hydroxybenzoic acid (13.8 g., 0.10 mole). The reaction temperature is then taken slowly to 140°-5° C. while stirring vigorously and maintained as such for 4 days. The reaction mixture is then cooled to room temperature and the inorganic solids removed by filtration prior to pouring the filtrate into water (1200 ml). The aqueous solution is then triturated with CCl4 (2 × 200 ml), decanted and then acidified to pH1 (conc. HCl) to give a tan colored solid, 25,6 g., mp 114°-17° C. This solid is further purified by dissolving in CCl4 (500 ml) and drying with anhydrous MgSO4. The CCl4 solution is reduced in vacuo to give 19.6 g. (62%) of a yellow solid, mp 116°-19° C. Recrystallization of the yellow solid from hexane gives a tan colored solid, 3-(2-chloro-4-trifluoromethylphenoxy)-benzoic acid, mp 122°-3° C.

1. customTo a 300 ml, 3-necked flask equipped with a condenser, stirrer
2. customdrying tube
3. customis then taken slowly to 140°-5° C.
4. temperaturemaintained as such for 4 days
5. customthe inorganic solids removed by filtration
6. additionto pouring the filtrate into water (1200 ml)
7. customThe aqueous solution is then triturated with CCl4 (2 × 200 ml)
8. customdecanted
9. customto give a tan colored solid, 25,6 g
10. customThis solid is further purified
11. dissolutionby dissolving in CCl4 (500 ml)
12. dry with materialdrying with anhydrous MgSO4
13. customto give 19.6 g
14. customRecrystallization of the yellow solid from hexane

ORDレコード

ord-ade202437c154813abd7b04ebec10f85

出典データセット

uspto-grants-1977_06

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US04031131