1,5-Dibromopentane → 4-[6-Bromo-1-[(4-methylphenyl)thio]hexyl]-1,2-dimethoxybenzene

反応式

[CH3:1][O:2][C:3]1[CH:8]=[CH:7][C:6]([CH2:9][S:10][C:11]2[CH:16]=[CH:15][C:14]([CH3:17])=[CH:13][CH:12]=2)=[CH:5][C:4]=1[O:18][CH3:19].C([Li])(C)(C)C.[Br:25][CH2:26][CH2:27][CH2:28][CH2:29][CH2:30]Br>O1CCCC1>[Br:25][CH2:26][CH2:27][CH2:28][CH2:29][CH2:30][CH:9]([C:6]1[CH:7]=[CH:8][C:3]([O:2][CH3:1])=[C:4]([O:18][CH3:19])[CH:5]=1)[S:10][C:11]1[CH:12]=[CH:13][C:14]([CH3:17])=[CH:15][CH:16]=1

参加物

実験手順

A solution of 13.72 g of 1,2-dimethoxy-4-[[(4-methylphenyl)thio]methyl]benzene in 200 mL of tetrahydrofuran (dried over 3A sieves), under nitrogen, is cooled to -78° C. and 30 mL of 1.7M t-butyl lithium is added. After 30 minutes, the solution is transferred, via a canula, into a stirred solution of 14.0 mL of 1,5-dibromopentane in 25 ml of tetrahydrofuran, under nitrogen at -78° C. The reaction is slowly warmed to room temperature, and the reaction is quenched by the addition of 4 mL of acetone. The reaction is concentrated in vacuo and the residual material is dissolved in ethyl acetate and is washed with brine. Drying (sodium sulfate) and solvent removal affords 33.22 g of oil. The residue is purified via chromatography on silica gel with gradient elution progressing from hexane to chloroform to methyl alcohol to afford 10.82 g of the desired product as a tan gum.