ClN1C(=O)CCC1=O.[NH2:9][C:10]1[CH:11]=[C:12]([CH:18]=[CH:19][C:20]=1[Cl:21])[C:13]([O:15][CH2:16][CH3:17])=[O:14].[CH3:22][S:23][CH3:24].C(N(CC)CC)C>ClCCl>[NH2:9][C:10]1[C:11]([CH2:22][S:23][CH3:24])=[C:12]([CH:18]=[CH:19][C:20]=1[Cl:21])[C:13]([O:15][CH2:16][CH3:17])=[O:14]N-chlorosuccinimide (215 g) was added during 10 minutes to a solution containing ethyl 3-amino-4-chlorobenzoate (108 g) and dimethyl sulphide (117 ml) in dichloromethane maintaining below 0° C. Triethylamine (80 ml) was added and after 20 minutes further additions of dimethyl sulphide (117 ml), N-chlorosuccinimide (215 g) and triethylamine (80 ml) were made. After 0.5 hours additional triethylamine (280 ml) was introduced, the mixture heated under reflux conditions overnight and evaporated. Ether was added and this was washed with water, dilute sodium bicarbonate, dried (magnesium sulphate) and evaporated. Purification by chromatography, eluting with ethyl acetate/petroleum ether gave ethyl 3-amino-4-chloro-2-methylsulphenylmethylbenzoate (47.6 g), NMR (CDCl3) 1.45 (t,3H), 2.1 (s,3H), 4.1 (s,2H), 4.3 (q,2H), 4.7 (s,2H), 7.2 (m,2H).
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