反应详情

To a solution of crude methyl 4-[(2-chloroethyl)amino]-3,5-dinitrobenzoate (D208) (9 g, 19.2 mmol, 1 equiv) in MeOH (75 ml) and cyclohexene (150 ml) was added 10% palladium on charcoal (50% wet, 4.5 g, 25% w/w) and the resulting mixture was refluxed for 3 h then cooled to room temperature. The catalyst was filtered off through a pad of celite and most of the solvent was removed in vacuo. The residue was partitioned between AcOEt and a 2N aqueous HCl solution and the two layers were separated. The aqueous phase was extracted twice with AcOEt and the combined organic layers were washed with a saturated aqueous NaHCO3 solution, dried over MgSO4 and concentrated in vacuo. Purification of the residue by flash chromatography on silica gel (iso-hexane/AcOEt: 1/1) gave methyl 8-nitro-1,2,3,4-tetrahydro-6-quinoxalinecarboxylate (D209) (1.5 g, 34%) as a red solid. [M−H]−=236.2, RT=2.65 min.

1. temperaturethe resulting mixture was refluxed for 3 h
2. filtrationThe catalyst was filtered off through a pad of celite and most of the solvent
3. customwas removed in vacuo
4. customThe residue was partitioned between AcOEt
5. customa 2N aqueous HCl solution and the two layers were separated
6. extractionThe aqueous phase was extracted twice with AcOEt
7. washthe combined organic layers were washed with a saturated aqueous NaHCO3 solution
8. dry with materialdried over MgSO4
9. concentrationconcentrated in vacuo
10. customPurification of the residue by flash chromatography on silica gel (iso-hexane/AcOEt: 1/1)