Sulfuric Acid → 2-[(2-Hydroxyphenyl)sulfanyl]-4-nitrobenzoic acid

Participants

Reaction Steps

Suspend 10.15 g (35 mmoles) of the amino acid of Step A in 75 ml of water and add 4 ml concentrated sulfuric acid (7.36 g, 75 mmoles, 150 meq). Cool the mixture in an ice-bath and add 3.657 g (53 mmoles) of sodium nitrite in portions at 0°-5° C. Stir the suspension in the cold for 20 minutes. Add 10 g (91 mmoles) of sodium fluoroborate and stir for an additional 20 minutes. Separate the precipitated crude diazonium fluoroborate, suspend the precipitate in 250 ml of 50% sulfuric acid and heat in an oil bath at 90°-100° C. for 45 minutes. Cool the mixture and separate the precipitate. (Yield: 7.76 g).

Provenance & Evidence