Potassium Hydroxide → 2-Amino-5-fluorobenzene-1-thiol

Participants

Reaction Conditions

Reaction Steps

In a 2,000-ml flask as a reactor were placed 166.7 g of water, 589.3 g of a 50% aqueous potassium hydroxide solution (5.25 moles as KOH) and 168.2 g (1.00 mole) of 6-fluoro-2-aminobenzothiazole. They were heated, aged for 8 hours with refluxing at 113 to 115° and then cooled to 40° C. The resulting mixture was washed with 311 g of toluene and then subjected to phase separation to obtain 904.0 g of an aqueous solution of a potassium salt of 2-amino-5-fluorothiophenol (concentration: 20%, yield: 99.7%). This aqueous solution of a potassium salt of 2-amino-5-fluorothiophenol can be used for production of a p-toluenesulfonate of [2-(6-fluorobenzothiazolyl)]ethylamine or an aqueous solution of [2-(6-fluorobenzothiazolyl)]ethylamine hydrochloride, according to the description in Example 1 to Example 7.

Provenance & Evidence