[Cl:1][C:2]1[CH:8]=[CH:7][C:6](=O)[C:5]([NH:10][C:11](=[O:16])[CH2:12][C:13](=[O:15])[CH3:14])=[CH:4][CH:3]=1.[O-]CC.[Na+].[Na].Br[CH2:23][C:24]([O:26][CH2:27][CH3:28])=[O:25]>CO>[CH2:27]([O:26][C:24](=[O:25])[CH2:23][N:10]1[C:11](=[O:16])[C:12]([C:13](=[O:15])[CH3:14])=[C:6]2[CH:7]=[CH:8][C:2]([Cl:1])=[CH:3][CH:4]=[C:5]12)[CH3:28]A mixture of 1-[(4-chloro-7-oxo-1,3,5-cycloheptatrien-1-yl)amino]-1,3-butanedione (5.8 g) and sodium ethoxide solution, prepared by dissolving 1.1 g of sodium in 200 ml of anhydrous, methanol-free ethanol, was heated at reflux for 5 hr. Thereafter, ethyl bromoacetate (10 ml) was added dropwise to the hot solution and refluxing was continued for an additional 10 min. The reaction mixture was evaporated to dryness. The residue was dissolved in chloroform and the solution filtered through a column of silica gel. Evaporation of the eluate gave 3.75 g of 3-acetyl-6-chloro-1,2-dihydro-2-oxocyclohepta[b]pyrrole-1-acetic acid ethyl ester, identical to the compound obtained from method A. Crystallization of the latter compound gave the product with mp 183.5° C.; nmr (CDCl3) δ1.27 (t, 3H), 2.7 (s, 3H), 4.2 (q, 2H), 4.85 (s, 2H), 6.85-9.3 (m, 4H); ir (white mineral oil) 1725, 1685 cm-1 ; uvλmax (MeOH) 293 nm (ε21,995), 256 (14,630), 231 (16,945); Anal Calcd for C15H14ClNO4 : C, 58.55% H, 4.59% N, 4.55%; Found: C, 58.53% H, 4.60% N, 4.54%.
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