[Cl:1][C:2]1[N:7]=[CH:6][C:5]([CH2:8][NH:9][C:10]2[CH2:14][O:13][C:12](=[O:15])[CH:11]=2)=[CH:4][CH:3]=1.[H-].[Na+].Br[CH2:19][CH:20]=[C:21]([Cl:23])[Cl:22].CO>O1CCCC1>[Cl:1][C:2]1[N:7]=[CH:6][C:5]([CH2:8][N:9]([CH2:19][CH:20]=[C:21]([Cl:23])[Cl:22])[C:10]2[CH2:14][O:13][C:12](=[O:15])[CH:11]=2)=[CH:4][CH:3]=1
350 mg (1.56 mmol) of 4-[[(6-chloropyridin-3-yl)methyl]amino]furan-2(5H)-one (Ia-1; cf. EP 0539588 A1) and 124 mg (3.12 mmol) of a 60% dispersion of sodium hydride in mineral oil in 100 ml of tetrahydrofuran are heated under reflux for 3 h. After cooling to room temperature, 592 mg (3.12 mmol) of 3-bromo-1,1-dichloroprop-1-ene (cf. WO 8800183 A1) are added and the mixture is heated under reflux for a further 5 h. After cooling of the reaction mixture to room temperature and addition of methanol, the mixture is concentrated under reduced pressure. The residue is taken up in ethyl acetate and the mixture is washed successively twice with 1 N aqueous hydrochloric acid, twice with 1 N aqueous sodium hydroxide solution and once with saturated sodium chloride solution. The organic phase is then dried over sodium sulphate and concentrated under reduced pressure. Purification of the residue by column chromatography on silica gel (silica gel 60—Merck, particle size: 0.04 to 0.063 mm) using the mobile phase mixture ethyl acetate:cyclohexane (2:1) gives 264 mg (50% of theory) of 4-[[(6-chloropyridin-3-yl)methyl](3,3-dichloroprop-2-en-1-yl)amino]furan-2(5H)-one.
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