Reacción #43996

Ecuación de reacción

n-Butyl lithium

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

ethyl chloroformate

→

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

Rendimiento 89.0%

Disolventes

tetrahydrofuran

Condiciones de reacción

Tratamiento posterior

1. 1
   Otroquenched by addition of hydrochloric acid (2N)
2. 2
   Extracciónextracted with ethyl acetate
3. 3
   SecadoThe extract was dried (Na2SO4)
4. 4
   Otrothe solvent evaporated under vacuum
5. 5
   OtroThe residue was purified by SPE (silica, 10 g)
6. 6
   Lavadoeluting with 10% ethyl acetate in cyclohexane

Procedimiento

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%).

Fuente