تفاعل #51859

معادلة التفاعل

triethylamine

benzyl alcohol

3,4-dimethoxyphenylacetic acid

thionyl chloride

→

title compound

المردود 60.1%

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

المردود 60.1%

المذيبات

Water

dichloromethane

dichloromethane

1,2-dichloroethane

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةThe resulting solution was heated
2. 2
   درجة الحرارةto reflux for 16 hours
3. 3
   أخرىthe volatile fractions removed in vacuo
4. 4
   أخرىResidual thionyl chloride was removed by an azeotrope with toluene (3×200 cm3)
5. 5
   أخرىto afford a crude brown oil
6. 6
   درجة الحرارةcooled to 0° C. in an ice bath
7. 7
   درجة الحرارةwarmed to ambient temperature
8. 8
   استخلاصthe aqueous extracted with dichloromethane (2×100 cm3)
9. 9
   تجفيفThe combined dichloromethane extracts were dried over sodium sulfate, vacuum
10. 10
    ترشيحfiltered
11. 11
    أخرىthe filtrate volatile fractions removed in vacuo
12. 12
    أخرىto afford a crude brown oil
13. 13
    أخرىThe crude product was purified by column chromatography (silica, eluting with hexane-ethyl acetate 1:0 to 1:1)

الإجراء التجريبي

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.

المصدر