Methanol → 2-Amino-3-chlorobenzoic acid

To a stirred solution of 3-chloro-2-nitrobenzoic acid (2.01 g, 10.0 mmol) in anhydrous methanol (100 mL) nickel(II)chloride hexahydrate (4.75 g, 20.0 mmol) was added, and the reaction mixture was cooled to room temperature. To this green solution was added NaBH4 (2.27 g, 60.0 mmol) in small portions over a period of 20 min. After the addition was complete, the reaction mixture was stirred at room temperature for 16 hours. The solvents were removed under vacuum and water (100 mL) was added, before neutralization to pH approximately equal to 4 with aqueous 2 N HCl. After extraction with methylene chloride (2×100 mL), the organic phase was separated, washed with water (100 mL), then brine (100 mL), and dried over anhydrous Na2SO4. The solvent was removed under vacuum to give 2-amino-3-chlorobenzoic acid as an off-white solid. Yield 0.90 g (52%).

1. additionAfter the addition
2. customThe solvents were removed under vacuum and water (100 mL)
3. additionwas added, before neutralization
4. extractionAfter extraction with methylene chloride (2×100 mL)
5. customthe organic phase was separated
6. washwashed with water (100 mL)
7. dry with materialbrine (100 mL), and dried over anhydrous Na2SO4
8. customThe solvent was removed under vacuum

ORD record

ord-21931511fa774120bfc32c59b9679c88

Source dataset

uspto-grants-2015_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08952021B2