反应详情

To a solution of bromobenzene 9 (0.21 g) in dry tetrahydrofuran (5 mL) cooled to −78° C. was added n-butyl lithium (0.38 mL, 2.5 M, 1.1 eq.). The solution was stirred for 30 min. and 3,4,5-trimethoxybenzoyl chloride (0.2 g) in anhydrous tetrahydrofuran was added. The resulting solution was then stirred for an additional 28 hours. The reaction was stopped with water, extracted with ethyl acetate and the solvent removed (in vacuo) to give a yellow oil. Separation by flash column chromatography (hexane-ethyl acetate, 3:1) afforded a colorless solid (0.06 g, 20.5%). The solid was recrystallized twice from ethyl acetate-hexane: m.p. 124.6-125.9° C., lit22 m.p. 121° C.; EIMS m/z 362 (M+), 345, 317, 181, 169, 151; 1H NMR δ 7.11 (1H, d, J=9.0 Hz, H6), 7.08 (2H, s, H2,6), 6.72 (1H, d, J=9.0 Hz, H5′), 3.94 (3H, s, OCH3), 3.93 (3H, s, OCH3), 3.90 (3H, s, OCH3), 3.85 (6H, s, OCH3,3,5), 3.80 (3H, s, OCH3).

1. stirringThe resulting solution was then stirred for an additional 28 hours
2. extractionextracted with ethyl acetate
3. customthe solvent removed (in vacuo)
4. customto give a yellow oil
5. customSeparation by flash column chromatography (hexane-ethyl acetate, 3:1)