3-Amino-5-(methanesulfonyl)benzoic acid → 3-Hydroxy-5-methylsulfonylbenzoic acid

Participants

Reaction Conditions

Reaction Steps

3-Amino-5-methylsulphonylbenzoic acid (D12) (7.24 g) was dissolved in a mixture of conc H2SO4 (100 ml) and water (300 ml) and cooled to 5° C. sodium nitrite (5.1 g) in water (15 ml) was added dropwise and the mixture was thereafter stirred in the cooling bath for 15 min and with the cooling bath removed for 40 min. It was then heated at 90° C. for 1 h. The heating was removed and the reaction was allowed to stand overnight. The mixture was partially neutralised (˜pH1) with solid sodium bicarbonate until a solid precipitate formed. The mixture was extracted 3 times with ethyl acetate and the combined extracts were washed with water and brine, dried (Mg SO4) and evaporated to a solid which was triturated with ether to give D13 (2 crops, 4.12 g).

Provenance & Evidence