Reacción #79745

Ecuación de reacción

ethyl bromoacetate

4-methoxyindole

n-butyl lithium

→

ethyl [4-methoxyindol-3-yl]acetate

Disolventes

ethyl acetate

tetrahydrofuran

Condiciones de reacción

Tratamiento posterior

1. 1
   OtroThe cooling bath was removed
2. 2
   Lavadowashed with water
3. 3
   Lavadowashed with brine
4. 4
   Secadodried over sodium sulfate
5. 5
   Otroevaporated in vacuo
6. 6
   OtroThe residue was chromatographed on silica gel eluting with a gradient hexane/10-50% ethyl ether
7. 7
   Otroto give

Procedimiento

To a solution of 2.94 gm (20 mmol) of 4-methoxyindole in 150 ml of tetrahydrofuran was added slowly 13 ml of n-butyl lithium (1.6M in hexane; 20 mmol) followed by the slow addition of 20 ml of zinc chloride (1.0M in ethyl ether; 20 mmol) at 0-5° C. The cooling bath was removed and the solution stirred for 2 hours and then treated with 2.1 ml (25 mmol) of ethyl bromoacetate for 19 hours, diluted with ethyl acetate, washed with water, washed with brine, dried over sodium sulfate, and evaporated in vacuo. The residue was chromatographed on silica gel eluting with a gradient hexane/10-50% ethyl ether to give starting material (40%) and then product, 2.3 gm, 50%, as an oil. 1H NMR (CDCl3) δ: 1.25 (t, 3H), 3.85 (s, 3H), 3.90 (s, 2H), 4.10 (q, 2H), 6.45 (d, 1H), 6.90 (d, 1H), 6.95 (s, 1H), 7.05 (t, 1H), 8.00 (br s, 1H).

Fuente