反应详情

Heat at 100° C. for 1 h a solution of 4-hydroxy-2-methyl-10-(2,4,6-trimethylphenyl)pyridino-[2,3-b]indolizine 2-methyl-9-(2,4,6-trimethylphenyl)pyrido[2,3-b]-indolizin-4-ol (10.1 g; 32 mmol) in phosphorus oxychloride (60 mL), cool to ambient temperature, and concentrate in vacuo. Partition the residue into ice water and CH2Cl2. Separate the aqueous phase, extract twice with CH2Cl2, and wash the combined organic extracts with a 1 N aqueous sodium hydroxide solution and then with water. Dry the solution over Na2SO4, filter, and concentrate in vacuo. Filter the dark residue through a short pad of silica gel and wash with 25% EtOAc in hexane. Concentrate the filtrate in vacuo to obtain the title compound as a yellow solid: 1H NMR (400 MHz, CDCl3) δ 2.00 (s, 6H), 2.37 (s, 3H), 2.64 (s, 3H), 6.58 (t, 1H), 6.95 (dd, 1H), 7.00 (s, 2H), 7.07 (s, 1H), 7.08 (d, 1H), 9.26 (d, 1H).

1. concentrationconcentrate in vacuo
2. customPartition the residue into ice water and CH2Cl2
3. customSeparate the aqueous phase
4. extractionextract twice with CH2Cl2
5. washwash the combined organic extracts with a 1 N aqueous sodium hydroxide solution
6. dry with materialDry the solution over Na2SO4
7. filtrationfilter
8. concentrationconcentrate in vacuo
9. filtrationFilter the dark residue through a short pad of silica gel
10. washwash with 25% EtOAc in hexane
11. concentrationConcentrate the filtrate in vacuo