Реакция #43996

Уравнение реакции

n-Butyl lithium

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

ethyl chloroformate

→

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

Выход 89.0%

Растворители

tetrahydrofuran

Условия реакции

Обработка

1. 1
   Другоеquenched by addition of hydrochloric acid (2N)
2. 2
   Экстракцияextracted with ethyl acetate
3. 3
   СушкаThe extract was dried (Na2SO4)
4. 4
   Другоеthe solvent evaporated under vacuum
5. 5
   ДругоеThe residue was purified by SPE (silica, 10 g)
6. 6
   Промывкаeluting with 10% ethyl acetate in cyclohexane

Методика

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%).

Источник