تفاعل #54958

معادلة التفاعل

acetyl chloride

methyl 2-(4-methoxyphenyl)propionate

boron trichloride

→

oil

Methyl 2-(3-acetyl-4-hydroxyphenyl)propionate

المذيبات

dichloromethane

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةcooled in an ice/salt-bath, at a rate sufficient
2. 2
   درجة الحرارةto maintain the temperature between -10° C. and -5° C
3. 3
   درجة الحرارةto maintain the temperature below 0° C
4. 4
   workup.ADDITIONwas added
5. 5
   workup.STIRRINGStirring
6. 6
   workup.WAITwas continued for 1/2 hour at +3° C.
7. 7
   workup.ADDITIONbefore pouring on
8. 8
   أخرىto crushed ice/concentrated hydrochloric acid
9. 9
   أخرىseparating the two phases
10. 10
    استخلاصThe aqueous phase was extracted with ether (3x)
11. 11
    غسيلthe combined organic extracts were washed with saturated sodium bicarbonate solution, saturated brine solution
12. 12
    تجفيفdried over anhydrous magnesium sulphate
13. 13
    أخرىEvaporation of the solvent
14. 14
    أخرىyielded the crude product as a pale yellow oil
15. 15
    workup.DISTILLATIONVacuum distillation

الإجراء التجريبي

Titanium tetrachloride (82.3 mls) was added dropwise to a stirred solution of methyl 2-(4-methoxyphenyl)propionate (25 g) in dry dichloromethane (250 mls), cooled in an ice/salt-bath, at a rate sufficient to maintain the temperature between -10° C. and -5° C. The mixture was stirred for 10 minutes and acetyl chloride (10 g) was added dropwise at a rate sufficient to maintain the temperature below 0° C. The solution was stirred at -5° C. for 11/2 hours when boron trichloride (15 mls) was added. Stirring was continued for 1/2 hour at +3° C. before pouring on to crushed ice/concentrated hydrochloric acid and separating the two phases. The aqueous phase was extracted with ether (3x) and the combined organic extracts were washed with saturated sodium bicarbonate solution, saturated brine solution, and dried over anhydrous magnesium sulphate. Evaporation of the solvent yielded the crude product as a pale yellow oil. Vacuum distillation furnished a pale yellow oil bp 120°-125° C./0.15 mm (16.2 g; 59%)

المصدر