Reaktion #11223

Reaktionsgleichung

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

Lösungsmittel

xylene

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturwere heated
2. 2
   Temperaturat reflux for 18 hours
3. 3
   Einengenbefore being concentrated in vacuo
4. 4
   Sonstigechromatographed on silica eluting with ethyl acetatelhexane (1:2)
5. 5
   SonstigeCrystallisation from ethyl acetate/hexane

Vorschrift

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.

Quelle