[CH3:1][O:2][C:3](=[O:19])[CH:4]([C:9]1[CH:14]=[CH:13][C:12]([N+:15]([O-:17])=[O:16])=[CH:11][C:10]=1[Cl:18])C(OC)=O.[Cl-].[Na+].CS(C)=O.O>CCOC(C)=O>[CH3:1][O:2][C:3](=[O:19])[CH2:4][C:9]1[CH:14]=[CH:13][C:12]([N+:15]([O-:17])=[O:16])=[CH:11][C:10]=1[Cl:18]2-(2-Chloro-4-nitro-phenyl)-malonic acid dimethyl ester (6.0 g, 20.9 mmol) and sodium chloride (2.2 g, 37.6 mmol) were added to a mixture of DMSO (100 mL) and water (0.38 mL, 20.9 mmol) and the reaction mixture was heated for 8 hours at 110° C. The reaction mixture was cooled to RT and poured into water (500 mL). EtOAc (200 mL) was added to the mixture which was then stirred for 15 minutes. The separated aqueous phase was extracted with EtOAc (100 mL). The combined organic extracts were washed with brine (100 mL), dried (Na2SO4) and the solvents removed under reduced pressure. The residue was purified by column chromatography on neutral silica gel using 3-6% EtOAc in hexane to give the title compound (2.9 g, 60%).
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