반응 #51859

반응 방정식

triethylamine

benzyl alcohol

3,4-dimethoxyphenylacetic acid

thionyl chloride

→

title compound

수율 60.1%

(3,4-Dimethoxy-phenyl)-acetic acid benzyl ester

수율 60.1%

용매

Water

dichloromethane

dichloromethane

1,2-dichloroethane

반응 조건

후처리

1. 1
   온도The resulting solution was heated
2. 2
   온도to reflux for 16 hours
3. 3
   기타the volatile fractions removed in vacuo
4. 4
   기타Residual thionyl chloride was removed by an azeotrope with toluene (3×200 cm3)
5. 5
   기타to afford a crude brown oil
6. 6
   온도cooled to 0° C. in an ice bath
7. 7
   온도warmed to ambient temperature
8. 8
   추출the aqueous extracted with dichloromethane (2×100 cm3)
9. 9
   건조The combined dichloromethane extracts were dried over sodium sulfate, vacuum
10. 10
    여과filtered
11. 11
    기타the filtrate volatile fractions removed in vacuo
12. 12
    기타to afford a crude brown oil
13. 13
    기타The crude product was purified by column chromatography (silica, eluting with hexane-ethyl acetate 1:0 to 1:1)

실험 절차

To a stirred mixture of commercially available 3,4-dimethoxyphenylacetic acid (100.0 g, 510 mmol) in anhydrous 1,2-dichloroethane (500 cm3) at ambient temperature under an atmosphere of dry nitrogen was added thionyl chloride (112 cm3, 1.53 mol) portionwise over 20 minutes. The resulting solution was heated to reflux for 16 hours. The brown solution was cooled to ambient temperature and the volatile fractions removed in vacuo. Residual thionyl chloride was removed by an azeotrope with toluene (3×200 cm3) to afford a crude brown oil. The crude oil was dissolved in anhydrous dichloromethane (400 cm3) and cooled to 0° C. in an ice bath. To the cooled solution was added triethylamine (75 cm3, 535 mmol) dropwise over 10 minutes followed by a solution of benzyl alcohol (50 cm3, 485 mmol) dissolved in anhydrous dichloromethane (200 cm3). The mixture was stirred for 20 hours and warmed to ambient temperature. Water was added to the mixture (700 cm3) and the aqueous extracted with dichloromethane (2×100 cm3). The combined dichloromethane extracts were dried over sodium sulfate, vacuum filtered and the filtrate volatile fractions removed in vacuo to afford a crude brown oil. The crude product was purified by column chromatography (silica, eluting with hexane-ethyl acetate 1:0 to 1:1) to afford the title compound as a pale yellow viscous oil (83.4 g, 57.2%) with a positive ion ESI (M−1H)+287.3.

출처