[C:1]([NH:4][C:5]1[CH:16]=[CH:15][C:14]([Cl:17])=[CH:13][C:6]=1[CH:7]=[CH:8][C:9]([O:11]C)=[O:10])(=[O:3])[CH3:2].[H-].[Na+].[CH3:20]OS(OC)(=O)=O.[OH-].[Na+]>CN(C)C=O.C1(C)C=CC=CC=1.O>[Cl:17][C:14]1[CH:15]=[CH:16][C:5]([N:4]([CH3:20])[C:1](=[O:3])[CH3:2])=[C:6]([CH:13]=1)[CH:7]=[CH:8][C:9]([OH:11])=[O:10]
12.8 g of methyl 2-acetamido-5-chlorocinnamate are dissolved in 200 ml of dimethylformamide/toluene (1:1), and 1.6 g sodium hydride (80% in paraffin oil) are added. Stirring is effected for 30 minutes, and at 0° 7 g of dimethylsulphate are added drop by drop. After 2 hours additional stirring at room temperature, 500 ml of water and 50 ml of 2 N sodium hydroxide solution are added followed by washing with toluene. After acidification, extraction with methylene chloride, removing of the solvent and chromatografic purification one obtains 7.6 g of 5-chloro-2-(N-methyl-acetamido)-cinnamic acid as oil. This oil is stirred for 24 hours at 100° with 100 ml of 5 N hydrochloric acid; after cooling the pH is adjusted to 8.5 with dilute sodium hydroxide solution, and 10 g of sodium bicarbonate are added. 7.5 g of 3,4-dichlorobenzoyl chloride in 50 ml of toluene are added dropwise. Working up as in Example 1(a) yields 10.8 g of 5-chloro-2-(N-methyl-3,4-dichlorobenzamido)cinnamic acid, which are reacted without further purification for 2 days at room temperature with 200 ml of methanol under addition of 4 ml of concentrated sulphuric acid. Extraction with methylene chloride and working up yield 8.3 g of the corresponding methyl ester, which is reacted analogously to (a).
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