反应详情

A mixture of 3.26 g of 4-bromo-1-nitro-2-(propan-2-yloxy)benzene, 4.65 g of 2-methylpropan-2-yl 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3,6-dihydropyridine-1(2H)-carboxylate, 12.5 ml of a 3M solution of sodium carbonate and 350 mg of bis(triphenylphosphine)dichloropalladium(II) in 41 ml of dioxane is refluxed for 1 h 30. The mixture is diluted with 150 ml of water and 200 ml of ethyl acetate. The aqueous phase is extracted three times with 200 ml of ethyl acetate. The combined organic phases are washed with 100 ml of a saturated sodium chloride solution, dried over magnesium sulfate and concentrated under vacuum. The residue is purified on 600 g of silica, elution being carried out with dichloromethane/ethyl acetate (99/1), so as to give 2.95 g of 2-methylpropan-2-yl 4-[4-nitro-3-(propan-2-yloxy)phenyl]-3,6-dihydropyridine-1(2H)-carboxylate in the form of a yellow solid.

1. temperatureis refluxed for 1 h 30
2. extractionThe aqueous phase is extracted three times with 200 ml of ethyl acetate
3. washThe combined organic phases are washed with 100 ml of a saturated sodium chloride solution
4. dry with materialdried over magnesium sulfate
5. concentrationconcentrated under vacuum
6. customThe residue is purified on 600 g of silica, elution