Reacción #11223

Ecuación de reacción

trans-diene

2-[2-(2-Chlorophenyl)ethenyl]-5-methoxy-1H-indole

maleic anhydride

→

4-(2-Chlorophenyl)-9-methoxy-4,5,6,10c-tetrahydro-1H-furo[3,4-c]carbazole-1,3(3aH)-dione

Disolventes

xylene

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturawere heated
2. 2
   Temperaturaat reflux for 18 hours
3. 3
   Concentraciónbefore being concentrated in vacuo
4. 4
   Otrochromatographed on silica eluting with ethyl acetatelhexane (1:2)
5. 5
   OtroCrystallisation from ethyl acetate/hexane

Procedimiento

A solution of trans-diene (27) (0.30 g, 1.06 mmol) prepared as described in example 37 and maleic anhydride (0.16 g, 1.59 mmol) in xylene (30 mL) were heated at reflux for 18 hours, before being concentrated in vacuo and chromatographed on silica eluting with ethyl acetatelhexane (1:2). Crystallisation from ethyl acetate/hexane then gave anhydride (286) (0.29 g, 72%) as a pale brown powder, mp 189–191° C. 1H NMR δ (CD3)2SO] 11.16 (br s, 1H), 7.69 (dd, J=7.7, 1.4 Hz, 1H), 7.51 (dd, J=7.7, 1.4 Hz, 1H), 7.43 (ddd, J=7.7, 7.7, 1.4 Hz, 1H), 7.36 (ddd, J=7.7, 7.7, 1.4 Hz, 1H), 7.25 (d, J=8.6 Hz, 1H), 7.15 (d, J=2.4 Hz, 1H), 6.77 (dd, J=8.6, 2.4 Hz, 1H), 4.70 (d, J=7.7 Hz, 1H), 4.47 (dd, J=7.7, 3.5 Hz, 1H), 3.78 (s, 3H), 3.71–3.66 (m, 1H), 3.36 (dd, J=15.9, 13.0 Hz, 1H), 2.99 (dd, J=15.9, 4.1 Hz, 1H). Found: C, 65.85; H, 3.95; N, 3.70. C21H16ClNO4 requires: C, 66.06; H, 4.22; N, 3.67.

Fuente