[Cl:1][C:2]1[C:10]([Cl:11])=[C:9]([S:12]([CH3:15])(=[O:14])=[O:13])[CH:8]=[CH:7][C:3]=1[C:4]([OH:6])=O.[CH2:16]([N:18]1[C:22]([OH:23])=[CH:21][CH:20]=[N:19]1)[CH3:17].C1(N=C=NC2CCCCC2)CCCCC1.Cl>C(#N)C>[CH2:16]([N:18]1[C:22]([OH:23])=[C:21]([C:4](=[O:6])[C:3]2[CH:7]=[CH:8][C:9]([S:12]([CH3:15])(=[O:14])=[O:13])=[C:10]([Cl:11])[C:2]=2[Cl:1])[CH:20]=[N:19]1)[CH3:17]A solution of 500 mg (1.85 mmol) of 2,3-dichloro-4-methylsulfonylbenzoic acid and 240 mg (2.14 mmol) of 1-ethyl-5-hydroxypyrazole in 10 mL of dry acetonitrile was treated with 430 mg (2.08 mmol) of dicyclohexylcarbodiimide with stirring at ambient temperature for 0.5 hr. The precipitate that formed was removed by filtration and the filtrate was treated with 0.5 mL of triethylamine and 1 mL of acetone cyanohydrin. After 1 hr, the reaction mixture was partitioned between dichloromethane and 1N aqueous hydrochloric acid. The organic layer was extracted with dilute aqueous sodium bicarbonate solution and the basic aqueous solution obtained was acidified with dilute aqueous hydrochloric acid and extracted with dichloromethane. The organic extract was dried over sodium sulfate and concentrated by evaporation under reduced pressure to obtain 540 mg (81 percent of theory) of the title compound as an orange syrup.
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