[Cl:1][C:2]1[CH:14]=[CH:13][C:5]([O:6][CH2:7][C:8]([O:10][CH2:11][CH3:12])=[O:9])=[C:4]([C:15]([O:17][CH3:18])=[O:16])[CH:3]=1.[N+:19]([O-])([OH:21])=[O:20]>S(=O)(=O)(O)O>[Cl:1][C:2]1[CH:14]=[C:13]([N+:19]([O-:21])=[O:20])[C:5]([O:6][CH2:7][C:8]([O:10][CH2:11][CH3:12])=[O:9])=[C:4]([C:15]([O:17][CH3:18])=[O:16])[CH:3]=1A solution of 620 g of ethyl 4-chloro-2-methoxycarbonylphenoxyacetate in 1600 ml of concentrated sulfuric acid is cooled below 0° C, and a mixture of 102 ml of fuming nitric acid (d 1.50) and 102 ml of concentrated sulfuric acid is added dropwise below 5° C. The resultant solution is stirred for 3 hours under ice-cooling and poured into ice-cold water and then extracted with ethyl acetate. The extract is washed with water twice and dried over magnesium sulfate. The solvent is distilled off and the residue is gradually crystallized to give 697 g of ethyl 4-chloro-2-methoxycarbonyl-6-nitrophenoxyacetate, melting at 68°-70° C.
Loading…