C(=O)([O-])[O-].[Li+].[Li+].[Br-].[Li+].Br[CH:10]1[CH2:16][CH2:15][CH2:14][C:13]2[CH:17]=[CH:18][C:19]([N+:21]([O-:23])=[O:22])=[CH:20][C:12]=2[C:11]1=[O:24]>CN(C)C=O>[N+:21]([C:19]1[CH:18]=[CH:17][C:13]2[CH2:14][CH2:15][CH:16]=[CH:10][C:11](=[O:24])[C:12]=2[CH:20]=1)([O-:23])=[O:22]A mixture of 548 g of lithium carbonate, 548 g of lithium bromide and 5.480 liters of dimethylformamide was heated to 100° C. and 548 g of the product of Step A was added thereto over 5 minutes. The mixture was held at 100° C. for 45 minutes and was then poured into 25 liters of a water-ice-mixture. The mixture was vacuum filtered and the insolubles were extracted 8 times with one liter of methylene chloride. The organic phase was washed with water, dried over sodium sulfate and evaporated to dryness under reduced pressure. The red crystalline mass was empasted successively 3 times with 400 ml of ether, once with 400 ml of ethanol and once with 400 ml of ether and was dried at 40° C. to obtain 286.7 g of 3-nitro-8,9-dihydro [5H] benzocycloheptene-5-one in the form of red-orange crystals melting at 128° C.
불러오는 중…
