반응 #43996

반응 방정식

n-Butyl lithium

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

ethyl chloroformate

→

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

수율 89.0%

용매

tetrahydrofuran

반응 조건

후처리

1. 1
   기타quenched by addition of hydrochloric acid (2N)
2. 2
   추출extracted with ethyl acetate
3. 3
   건조The extract was dried (Na2SO4)
4. 4
   기타the solvent evaporated under vacuum
5. 5
   기타The residue was purified by SPE (silica, 10 g)
6. 6
   세척eluting with 10% ethyl acetate in cyclohexane

실험 절차

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%).

출처