反应详情

A solution of 4-hydroxy-2-methyl-10-(2,4,6-trimethylphenyl)pyrido-[2,3-b]indolizine (10.1 g; 32 mmol) in phosphorus oxychloride (60 mL) is heated at 100° C. for 1 hour, cooled to room temperature, and concentrated in vacuo. The residue is partitioned into ice water and dichloromethane. The aqueous phase is separated and extracted twice with dichloromethane. The combined organics are washed with a 1 N aqueous sodium hydroxide solution and then with water. The solution is dried (Na2SO4), filtered, and concentrated in vacuo, and the resulting dark residue is filtered through a short pad of silica gel and washed with 25% ethyl acetate in hexane. The filtrate is concentrated in vacuo to give 10.1 g of the title compound as a yellow solid (94%): 1H nmr (400 MHz, CDCl3) d 2.00 (s, 6 H), 2.37 (s, 3 H), 2.64 (s, 3 H), 6.58 (t, 1 H), 6.95 (dd, 1 H), 7.00 (s, 2 H), 7.07 (s, 1 H), 7.08 (d, 1 H), 9.26 (d, 1 H).

1. concentrationconcentrated in vacuo
2. customThe residue is partitioned into ice water and dichloromethane
3. customThe aqueous phase is separated
4. extractionextracted twice with dichloromethane
5. washThe combined organics are washed with a 1 N aqueous sodium hydroxide solution
6. dry with materialThe solution is dried (Na2SO4)
7. filtrationfiltered
8. concentrationconcentrated in vacuo
9. filtrationthe resulting dark residue is filtered through a short pad of silica gel
10. washwashed with 25% ethyl acetate in hexane
11. concentrationThe filtrate is concentrated in vacuo