反応 #43996

反応方程式

n-Butyl lithium

2-bromo-1,4-dimethoxy-3-methylnaphthalene

ethyl chloroformate

→

ethyl 1,4-dimethoxy-2-methylnaphthalene-3-carboxylate

収率 89.0%

溶媒

tetrahydrofuran

反応条件

後処理

1. 1
   その他quenched by addition of hydrochloric acid (2N)
2. 2
   抽出extracted with ethyl acetate
3. 3
   乾燥The extract was dried (Na2SO4)
4. 4
   その他the solvent evaporated under vacuum
5. 5
   その他The residue was purified by SPE (silica, 10 g)
6. 6
   洗浄eluting with 10% ethyl acetate in cyclohexane

実験手順

n-Butyl lithium (1.6M in hexanes, 4.1 ml, 6.56 mmol) was added dropwise to 2-bromo-1,4-dimethoxy-3-methylnaphthalene (1.537 g, 5.47 mmol) in tetrahydrofuran (30 ml) at −50° C. The reaction was stirred for 30 min at −50° C. before dropwise addition of ethyl chloroformate (1 ml, 10.46 mmol). The reaction was allowed to warm to 0° C. over 18 h quenched by addition of hydrochloric acid (2N) and extracted with ethyl acetate. The extract was dried (Na2SO4) and the solvent evaporated under vacuum. The residue was purified by SPE (silica, 10 g) eluting with 10% ethyl acetate in cyclohexane to give ethyl 1,4-dimethoxy-2-methylnaphthalene-3-carboxylate (1.33 g, 89%).

出典