28% |
With 2,3-dicyano-5,6-dichloro-p-benzoquinone; In tetrahydrofuran; water; at 0 - 20℃; for 1.16667h; |
EXAMPLE 8; 3,4-dihvdrocycIopentafZ>1indol-l(2H)-one [Compound No. 81An ice-cooled solution of 1,2,3, 4-tetrahydrocyclopenta[Z>]indole (1.006 gm, 6.361 mmol) in a mixture of THF (15 mL) and water (1.5 mL) was deoxygenated by passing a stream of nitrogen through it for 10 minutes. It was then maintained under an atmosphere of nitrogen whilst a solution of 2,3-dichloro-5,6-dicyano-l,4-benzoquinone (3.206 g, 14.123 mmol) dissolved in THF (12 mL) was added dropwise over a period of 10 minutes. Stirring was then continued for a further hour, the reaction mixture being allowed to warm to room temperature during this period. Evaporation of the solvent then left a red-brown solid residue, which was applied to a chromatography column and the products eluted using ethyl acetate only. Three columns were used to purify this material. The product was obtained as a yellow solid (300 mg, 28%), mp252-255C (decomposition), RF=O.10 (ethyl acetate/n-hexane 1/1), [Rodriguez, J.G.; Temprano, F.; Esteban-Calderon, C; Martinez-Ripoll, M.; Garcia-Blanco, S., Tetrahedron, 1985, 41(18), 3813-3823, mp257-259C]. IR (KBr): 3210, 1655, 1614, 1471, 1429, 1241, 1152, 1047, 738 cm/1 1H NMR (DMSOd6): 12.01(1H, br); 7.67(1H, d, J=7.3Hz); 7.45(1H, d, J=7.3Hz); 7.21(1H, dt, J=7.2Hz & 1.4Hz); 7.15(1H, dt, J=7.2Hz & 1.4Hz); 3.08(2H5 m); 2.82(2H, m). EPO <DP n="23"/> |