3,4-Dibromothiophene → 3-Bromo-4-(1-oxopropyl)thiophene
Reaction equation
Br[C:2]1[C:6]([Br:7])=[CH:5][S:4][CH:3]=1.C([Li])CCC.CN(OC)[C:15](=[O:18])[CH2:16][CH3:17]>CCOCC>[Br:7][C:6]1[C:2]([C:15](=[O:18])[CH2:16][CH3:17])=[CH:3][S:4][CH:5]=1Participants
5
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Procedure
A solution of 3,4-dibromothiophene (6.0 g, 24.8 mmol) in 10 mL of ether was cooled to -78° C. and trated with n-butyllithium (9.92 mL, 2.5M solution in hexanes, 24.8 mmol). While holding the temperature at -78° C., the reaction was stirred for 15 minutes, then 2.9 g (24.8 mmol) of N-methyl-N-methoxypropionamide was added and the reaction was stirred for 1 hour. The reaction was quenched with satd NH4Cl, and the mixture was diluted with ether. The ether layer was separated, washed with water and brine, dried over MgSO4 and concentrated. The residue was triturated with hexanes, and the mixture was filtered. The solvent was removed to give 2.08 g of a tan solid. MS 236, 238 (M+NH4)+. NMR (CDCl3) δ:7.99 (d, J=3 Hz, 1H), 7.32 (d, J=3 Hz, 1H), 2.98 (q, J=7 Hz, 2H), 1.21 (t, J=7 Hz, 3H).