تفاعل #355608

معادلة التفاعل

(±)- 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid

sodium hydroxide

benzyl chloride

(±)-benzyl 6-benzyloxy-2,5,7,8-tetramethylchroman-2-carboxylate

potassium carbonate

→

(±)- 6-benzyloxy-2,5,7,8-tetramethylchroman-2-carboxylic acid

المذيبات

H2O

dimethylsulfoxide

dimethylsulfoxide

ظروف التفاعل

المعالجة

1. 1
   workup.ADDITIONTo a mixture of 0.5 g
2. 2
   أخرىto give a solution
3. 3
   workup.ADDITIONTo this solution was added 3 ml
4. 4
   درجة الحرارةThe mixture was cooled
5. 5
   غسيلwashed with ether
6. 6
   استخلاصextracted with ether
7. 7
   غسيلThe ether solutions were washed with brine
8. 8
   تجفيفdried over sodium sulfate
9. 9
   أخرىThe residue was crystallized from ether-30°-60° petroleum ether

الإجراء التجريبي

To a mixture of 0.5 g. of (±)- 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid and 1.3 g. of anhydrous potassium carbonate in 3 ml. of dimethylsulfoxide was added 1.0 g. of benzyl chloride. This mixture was stirred at 23° overnight to give a solution containing (±)-benzyl 6-benzyloxy-2,5,7,8-tetramethylchroman-2-carboxylate. To this solution was added 3 ml. of 1N sodium hydroxide solution and 2 ml. of dimethylsulfoxide and the resulting 2-phase solution was stirred at 100° for 16 hours. The mixture was cooled, diluted with H2O, washed with ether, acidified with 2N HCl, and extracted with ether. The ether solutions were washed with brine, dried over sodium sulfate and stripped of solvent. The residue was crystallized from ether-30°-60° petroleum ether to give (±)- 6-benzyloxy-2,5,7,8-tetramethylchroman-2-carboxylic acid as a white solid, m.p. 154.5°-155°.

المصدر