반응 #7107

반응 방정식

2-bromo-3-methylthiophene

diethylamine

n-BuLi

DMF

→

subtitled compound

5-Bromo-4-methyl-2-thiophene carboxaldehyde

용매

THF

THF

hexane

반응 조건

후처리

1. 1
   workup.ADDITIONAfter addition
2. 2
   온도cooled to −78° C.
3. 3
   workup.STIRRINGThe reaction solution was stirred at −78° C. for 30 minutes
4. 4
   온도to warm to ambient temperature
5. 5
   기타was quenched with 1N aqueous hydrochloride solution (1 L)
6. 6
   추출The solution was extracted with ethyl acetate(3×450 mL)
7. 7
   세척The extracts were washed with water, brine
8. 8
   건조dried (MgSO4)
9. 9
   기타After removal of solvent in vacuo

실험 절차

To a solution of diethylamine (28 g, 0.383 mol) in anhydrous THF (400 mL) was added at −40° C. under nitrogen a solution of n-BuLi (2.5 M, 153 mL, 0.383 mol) in hexane. After addition, the solution was stirred at −40° C. under nitrogen for 30 minutes, cooled to −78° C. and treated dropwise with a solution of 2-bromo-3-methylthiophene (45 g, 0.254 mol) in anhydrous THF (450 mL). The reaction solution was stirred at −78° C. for 30 minutes and treated with anhydrous DMF (100 mL). The mixture was allowed to warm to ambient temperature and was quenched with 1N aqueous hydrochloride solution (1 L). The solution was extracted with ethyl acetate(3×450 mL). The extracts were washed with water, brine and dried (MgSO4). After removal of solvent in vacuo, the subtitled compound was obtained as a white solid (46 g, 88.3%). A sample of the product was crystallized from hexane: mp 63–65° C.; IR (KBr) 1654 cm−1. 1H-NMR (CDCl3) δ 9.75 (s, 1H), 7.45 (s, 1H), 2.26 (s, 3H); MS (EI) m/z 204/206 (M+). Anal. Calc. For C6H5BrOS: C, 35.14; H, 2.46. Found: C, 35.00; H, 2.44.

출처