反应详情

Hydrazine hydrate (14.19 g, 283.5 mmol) was cooled to −50° C. and (4-cyclopropylsulfanylphenyl)oxoacetic acid (Preparation 1, 12.6 g, 56.7 mmol) added in one portion. The vigorously-stirred slurry was warmed firstly to room temperature and then at 80° C. for 5 min. Solid KOH (8.76 g, 156.5 mmol) was added in four equal portions and the resulting solution heated at 100° C. for 20 h. On cooling to room temperature, water (25 ml) was added and the aqueous phase washed with Et2O (20 ml). The ethereal phase was itself washed with water (2×15 ml) and sufficient concentrated HCl added to the combined aqueous phases to adjust the pH to 1. The resulting precipitate was then extracted into EtOAc (2×300 ml) and the combined organic phases washed with water (3×100 ml), brine (200 ml) then dried (MgSO4). Evaporation of the solvent afforded the title compound: m/z (ES−)=207.1 [M−H+]−.

1. temperaturethe resulting solution heated at 100° C. for 20 h
2. temperatureOn cooling to room temperature
3. washthe aqueous phase washed with Et2O (20 ml)
4. washwashed with water (2×15 ml) and sufficient concentrated HCl
5. additionadded to the combined aqueous phases
6. extractionThe resulting precipitate was then extracted into EtOAc (2×300 ml)
7. washthe combined organic phases washed with water (3×100 ml), brine (200 ml)
8. dry with materialthen dried (MgSO4)
9. customEvaporation of the solvent