Dimethylformamide → 3-Amino-4-(4-hydroxy-phenylsulfanyl)-benzoic acid methyl ester

A suspension of the product of Example 65A (as a mono DMF adduct) (7.25 g, 19.23 mmol) ammonium chloride (1.54 g, 28.8 mmol) and iron powder (5.37 g, 96.15 mmol) in tetrahydrofuran (75 mL), water (25 mL) and ethanol (75 mL) was heated at reflux for 3 hours. The reaction was cooled to room temperature, and the mixture was filtered through a pad of celite, which was then washed with methanol, and the filtrate concentrated to a solid under vacuum. The residue was then dissolved in water (100 mL) and extracted with dichloromethane (2×50 mL). The combined organic extracts were washed with brine (25 mL), dried over magnesium sulfate, filtered, and concentrated under vacuum to provide the title compound as a white solid (4.2 g, 79%).

1. temperaturewas heated
2. temperatureat reflux for 3 hours
3. filtrationthe mixture was filtered through a pad of celite, which
4. washwas then washed with methanol
5. concentrationthe filtrate concentrated to a solid under vacuum
6. dissolutionThe residue was then dissolved in water (100 mL)
7. extractionextracted with dichloromethane (2×50 mL)
8. washThe combined organic extracts were washed with brine (25 mL)
9. dry with materialdried over magnesium sulfate
10. filtrationfiltered
11. concentrationconcentrated under vacuum

ORD record

ord-f5338c8ab4fd4c4a89c74568dfa8bc03

Source dataset

uspto-grants-2012_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08236950B2