반응 #10372

반응 방정식

NaHCO3

ethanol

3-methyl-2,4,5-trifluorobenzoic acid

oxalyl chloride

→

title compound

수율 77.1%

2,4,5-Trifluoro-3-methylbenzoic acid ethyl ester

수율 77.1%

용매

dichloromethane

반응 조건

후처리

1. 1
   농축concentrated
2. 2
   기타dried in vacuo
3. 3
   workup.ADDITIONThe acid chloride is diluted with dichloromethane
4. 4
   온도cooled to 0° C.
5. 5
   workup.STIRRINGThe resulting solution is stirred at room temperature for 20 hours
6. 6
   추출extracted with dichloromethane
7. 7
   세척The organic extracts are washed with brine
8. 8
   건조dried over Na2SO4
9. 9
   여과filtered
10. 10
    농축concentrated under vacuum

실험 절차

A solution of 3-methyl-2,4,5-trifluorobenzoic acid (Shimizu T., Asai T., Kumai S., Jpn. Kokai Tokkyo Koho (1997) Japanese Appl. JP 95-219069, 4.3 g, 22.6 mmol) in dichloromethane (100 mL) at 0° C. is treated with oxalyl chloride (4.2 g, 33 mmol) followed by N,N-dimethylformamide (2 drops). The mixture is stirred at room temperature for 3 hours, concentrated and dried in vacuo. The acid chloride is diluted with dichloromethane, cooled to 0° C., and treated with absolute ethanol (10 mL, 170 mmol). The resulting solution is stirred at room temperature for 20 hours, poured into saturated NaHCO3 solution and extracted with dichloromethane. The organic extracts are washed with brine, dried over Na2SO4, filtered, and concentrated under vacuum to afford the title compound (3.8 g). 1H NMR (200 MHz, CDCl3): δ 7.67–7.26 (m, 1H), 4.44 (q, 2H), 2.27 (dd, 3H), 1.42 (t, 3H).

출처