[Cl:1][C:2]1[C:3]([C:8]([F:11])([F:10])[F:9])=[N:4][NH:5][C:6]=1[CH3:7].C(=O)([O-])[O-].[K+].[K+].[C:18]([O:22][C:23](=[O:26])CBr)([CH3:21])([CH3:20])[CH3:19]>C(#N)C>[C:18]([O:22][C:23]([N:5]1[C:6]([CH3:7])=[C:2]([Cl:1])[C:3]([C:8]([F:9])([F:11])[F:10])=[N:4]1)=[O:26])([CH3:21])([CH3:20])[CH3:19]To 2.70 mmol of 4-chloro-5-methyl-3-trifluoromethylpyrazole and 3.9 mmol of potassium carbonate in 0.5M solution of acetonitrile add 3.25 mmol of t-butylbromoacetate. The reaction was allowed to stir at room temperature for an hour and then heated at 70° C. for 12 hours. The reaction was filtered, the filtrate concentrated to a crude oil. Fresh ether was added and the mixture was allowed to cool. The white crystals obtained were filtered and vaccum dried to give the desired intermediate 4-chloro-5-methyl-3-trifluoromethylpyrazole-1-carboxylic acid tertbutyl ester in 95% yield. LC-MS in FP m/z=300 (M++1)
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