تفاعل #1049543

معادلة التفاعل

triphenylphosphine

1-O-octadecyl-2-O- benzyl-glycerol

toluene

carbon tetrabromide

→

1-O-octadecyl-2-O-benzyl-3-bromo-1,2-propanediol

المذيبات

chloroform

ظروف التفاعل

المعالجة

1. 1
   أخرىIn a 250 ml round bottom flask equipped with a magnetic stir bar
2. 2
   workup.ADDITIONTo this solution were added 4.58 g
3. 3
   ترشيحThe yellow suspension was filtered
4. 4
   تركيزthe filtrate concentrated on a rotary evaporator
5. 5
   أخرىto afford a white solid
6. 6
   غسيلwashed twice with 30 ml saturated sodium bicarbonate
7. 7
   تجفيفdried over anhydrous magnesium sulfate
8. 8
   تركيزconcentrated under vacuum on a rotary evaporator
9. 9
   أخرىto afford 2.5 g of the crude product as a white powder
10. 10
    أخرىThis crude product was purified by flash column chromatography on a silica gel 60 (E. Merck, Germany) column by sequential elution with 100 ml each of hexane, 1% ethyl acetate in hexane, 2% ethyl acetate in hexane and finally with 3% ethyl acetate in hexane
11. 11
    أخرىFractions collected
12. 12
    تركيزThe pooled fractions were concentrated under vacuum on a rotary evaporator

الإجراء التجريبي

In a 250 ml round bottom flask equipped with a magnetic stir bar, 2.00 g (4.6 mmoles) of 1-O-octadecyl-2-O- benzyl-glycerol (Bachem, Switzerland) was dissolved into 120 ml of toluene. To this solution were added 4.58 g. (13.8 mmoles) of carbon tetrabromide and 3.62 g. (13.8 mmoles) of triphenylphosphine and the reaction mixture stirred for 4 hours at room temperature. The yellow suspension was filtered and the filtrate concentrated on a rotary evaporator to afford a white solid. This residue was dissolved into 50 ml chloroform, washed twice with 30 ml saturated sodium bicarbonate, dried over anhydrous magnesium sulfate and concentrated under vacuum on a rotary evaporator to afford 2.5 g of the crude product as a white powder. This crude product was purified by flash column chromatography on a silica gel 60 (E. Merck, Germany) column by sequential elution with 100 ml each of hexane, 1% ethyl acetate in hexane, 2% ethyl acetate in hexane and finally with 3% ethyl acetate in hexane. Fractions collected were screened by TLC and those fractions that contained pure product (silica gel, 5% ethyl acetate in hexane, Rf=0.56) were pooled. The pooled fractions were concentrated under vacuum on a rotary evaporator to afford a quantitative yield of the 1-O-octadecyl-2-O-benzyl-3-bromo-1,2-propanediol as a white powder.

المصدر