Ethanethiol → 4-Amino-5-chloro-2-hydroxybenzoic acid

Temperatur

25 °C

A cooled (5° C.) suspension of 60% sodium hydride oil dispersion (20.0 g, 0.50 mole) in anhydrous dimethylformamide (300 ml) under nitrogen was treated dropwise with ethyl mercaptan (18.7 g, 0.3 mole) while maintaining the reaction temperature below 15° C. The solution was stirred for 15 minutes at 25° C., cooled (5° C.), and treated in small portions with 4-amino-5-chloro-2-methoxybenzoic acid (40.33 g, 0.2 mole). The mixture was heated to 105°±5° C. for 4 hours, cooled, concentrated in vacuo to remove most of the dimethylformamide, then diluted with water (500 ml). The aqueous solution was extracted with methylene chloride (2×150 ml), then with ether (150 ml), acidified with concentrated HCl (55 ml), filtered, and the filter cake was washed with water and dried in vacuo in the presence of Drierite to provide a crude product. The product was recrystallized from tetrahydrofuran/hexane to yield 31.3 g (83%) of white solid, mp 192° C.

1. temperatureA cooled
2. temperaturewhile maintaining the reaction temperature below 15° C
3. temperaturecooled (5° C.)
4. temperatureThe mixture was heated to 105°±5° C. for 4 hours
5. temperaturecooled
6. concentrationconcentrated in vacuo
7. customto remove most of the dimethylformamide
8. additiondiluted with water (500 ml)
9. extractionThe aqueous solution was extracted with methylene chloride (2×150 ml)
10. filtrationfiltered
11. washthe filter cake was washed with water
12. dry with materialdried in vacuo in the presence of Drierite
13. customto provide a crude product
14. customThe product was recrystallized from tetrahydrofuran/hexane

ORD-Eintrag

ord-7efec71635e9487ead43743c726bc72a

Quelldatensatz

uspto-grants-1993_12

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US05273972