反应详情

2.5 g (10 mmoles) of 2-[3-chloro-4-(pyrazol-1-yl)phenyl]propionic acid are dissolved in 30 ml of methylene chloride. A solution of 2.01 g (15 mmoles) of sulfuryl chloride in 10 ml of chloroform is added dropwise, with cooling to the resulting solution; heating is effected gradually to room temperature; and this is followed by boiling under reflux for 2 hours. The reaction solution is allowed to cool; the solvent is distilled off; 50 ml of 2 N solution of sodium hydroxide are added to the thus-obtained residue, and boiling up is effected for a few minutes. The reaction solution is extracted with diethyl ether and then acidified with hydrochloric acid. After renewed extraction with diethyl ether, the combined ether phases are dried and evaporated to produce 2.6 g (90% of theory) of 2-[3-chloro-4-(4-chloropyrazol-1-yl)phenyl]propionic acid, m.p. 102° to 103° C.

1. temperaturewith cooling to the resulting solution
2. temperatureheating
3. customis effected gradually to room temperature
4. temperatureunder reflux for 2 hours
5. temperatureto cool
6. distillationthe solvent is distilled off
7. addition50 ml of 2 N solution of sodium hydroxide are added to the thus-obtained residue
8. waitboiling up is effected for a few minutes
9. extractionThe reaction solution is extracted with diethyl ether
10. extractionextraction with diethyl ether
11. dry with materialthe combined ether phases are dried
12. customevaporated