Hydrochloric Acid → HCID 10932262, compound

Participants

Reaction Conditions

Reaction Steps

50 g (0.258 mol) of 2,3,4,5-tetrafluorobenzoic acid and 41.4 g (1.04 mol) of sodium hydroxide are introduced first into 687 g of water, the resulting solution is heated to 100° C. and stirred at this temperature for 12 to 14.5 hours. The end point of the reaction is determined by gas chromatography. 57.2 g of calcium chloride are then added, and the pH is brought to 1 with 30% hydrochloric acid. The solutionis continuously extracted with MTBE (methyl tert.-butyl ether) for 16 hours, and the solvent is then distilled off. The dry residue (44.6 g) is recrystallized at 145° C. from 1,2-dichlorobenzene to give 42.1 g (0.219 mol, 85%) of white to slightly beige-colored 4-hydroxy-2,3,5-trifluorobenzoic acid which gives the expected values in all analytical tests. The 3-hydroxy-2,4,5-trifluorobenzoic acid content ofless than 5 mol % of the crude product also formed in the reaction is completely removed by dissolution and reprecipitation (recrystallization).

Provenance & Evidence