反应详情

A solution of 1-ethyl-7-methoxy-2-(4-methoxyphenyl)indolizine (Compound 3) (2.0 g, 7.11 mmol) in 65 ml of toluene was stirred in an ice bath, while 3-butyn-2-one (0.64 ml, 8.17 mmol) was added dropwise. The cooling source was removed and stirring was continued for twenty hours. 2,3-Dichloro-5,6-dicyano-1,4-benzoquinone (1.73 g, 7.61 mmol) was added in portions and stirring was continued for twenty hours. The solvent was evaporated and the residue chromatographed over aluminium oxide with heptane/tetrahydrofuran (1:1) as eluent to afford 1.54 g (63%) of the title compound. M.p. 137-39° C. 1H-NMR (DMSO-d6, 200 MHz) δ: 1.39 (t, 3H), 2.64 (s, 3H), 3.15 (q, 2H), 3.87 (s, 3H), 4.09 (s, 3H), 7.19 (d, 2H), 7.80 (d, 2H), 7.82 (d, 1H), 7.89 (d, 1H), 8.15 (s, 1H). (Compound 6).

1. additionwas added dropwise
2. customThe cooling source was removed
3. waitwas continued for twenty hours
4. stirringstirring
5. waitwas continued for twenty hours
6. customThe solvent was evaporated
7. customthe residue chromatographed over aluminium oxide with heptane/tetrahydrofuran (1:1) as eluent