تفاعل #2507817

معادلة التفاعل

iodine

n-butyllithium

7-bromo-6-fluoro-3-propylchroman

→

6-fluoro-7-iodo-3-propylchroman

المذيبات

THF

hexane

THF

ظروف التفاعل

المعالجة

1. 1
   workup.ADDITIONare added
2. 2
   أخرىthe cooling is removed
3. 3
   workup.ADDITIONThe batch is diluted with MTB ether
4. 4
   غسيلwashed with water and with sat. sodium hydrogensulfite soln
5. 5
   تجفيفand dried over sodium sulfate
6. 6
   أخرىThe solvent is removed in vacuo
7. 7
   ترشيحthe crude product is filtered through silica gel with heptane/toluene (4:1)

الإجراء التجريبي

10.6 g (38.8 mmol) of 7-bromo-6-fluoro-3-propylchroman are initially introduced in 100 ml of THF, and 27 ml (43.0 mmol) of a 15 percent solution of n-butyllithium in hexane are added dropwise. After 90 min, 10.0 g (39.4 mmol) of iodine, dissolved in 50 ml of THF, are added, the mixture is stirred for 1 h, and the cooling is removed. The batch is diluted with MTB ether, washed with water and with sat. sodium hydrogensulfite soln. and dried over sodium sulfate. The solvent is removed in vacuo, and the crude product is filtered through silica gel with heptane/toluene (4:1), giving 6-fluoro-7-iodo-3-propylchroman as a colourless solid, which is sufficiently pure for further reaction.

المصدر