Potassium Nitrate → 2,4-Difluoro-5-nitrobenzoic acid

Participants

Reaction Steps

To 500 ml of conc. sulfuric acid was added 151 g of 2,4-difluorobenzoic acid. With ice cooling and stirring, 114 g of potassium nitrate powder was added thereto in portions over 30 minutes. Stirring was continued for a further 1 hour, yielding a sherbet-like precipitate. The reaction solution was poured into 1.5 L of ice water and stirred for 30 minutes. The precipitate was collected by filtration, washed with 1 L of distilled water, air dried, and then dried in vacua over phosphorus pentoxide to give 164.5 g of 2,4-difluoro-5-nitrobenzoic acid as colorless crystals.

Provenance & Evidence