تفاعل #2719

معادلة التفاعل

2-methylthiophene

n-BuLi

2,2-dimethyl-6-bromo-thiochroman-4-one

Compound M

2,2-dimethyl-6-bromo-thiochroman-4-one

→

title compound

2,2-Dimethyl-4(2-methyl-thien-5-yl)-6-bromo-thiochrom-3-ene

المذيبات

THF

hexane

THF

ether

ظروف التفاعل

المعالجة

1. 1
   أخرىwas recooled to -78° C.
2. 2
   workup.STIRRINGThe mixture was stirred for 16 hours at ambient temperature
3. 3
   غسيلwashed with water (10 mL), brine (10 mL)
4. 4
   أخرىdried
5. 5
   أخرىthe solvent was removed by evaporation
6. 6
   أخرىThe product was seperated by column chromatography
7. 7
   workup.DISSOLUTIONwas dissolved in dichloromethane (5 mL)
8. 8
   workup.ADDITIONTo this solution p-TSA (5 mg) was added
9. 9
   workup.STIRRINGthe mixture was stirred at ambient temperature for 5 min
10. 10
    أخرىThe reaction was quenched with 10% NaHCO3 (3 mL)
11. 11
    غسيلwashed with brine (5 mL)
12. 12
    أخرىdried
13. 13
    أخرىthe solvent was removed by distillation
14. 14
    أخرىThe residual crude material was purified by column chromatography

الإجراء التجريبي

To a cold (-78° C.) solution of 2-methylthiophene (1.2 g, 12.2 mmol) in THF (8 mL) was added n-BuLi in hexane (1.6M, 8.5 mL). The mixture was warmed to ambient temperature over 30 minutes. with stirring. The mixture was recooled to -78° C. and a solution of 2,2-dimethyl-6-bromo-thiochroman-4-one (Compound M, 1.4 g, 5.2 mmol) in THF (10 mL) was added. The mixture was stirred for 16 hours at ambient temperature. Then the reaction mixture was diluted with ether (125 mL), washed with water (10 mL), brine (10 mL) dried and the solvent was removed by evaporation. The product was seperated by column chromatography and was dissolved in dichloromethane (5 mL). To this solution p-TSA (5 mg) was added and the mixture was stirred at ambient temperature for 5 min. The reaction was quenched with 10% NaHCO3 (3 mL), washed with brine (5 mL), dried and the solvent was removed by distillation. The residual crude material was purified by column chromatography to obtain the title compound as a pale yellow oil.

المصدر