C[Si]([N-][Si](C)(C)C)(C)C.[Li+].[CH3:11][C:12]1[CH:17]=[CH:16][N:15]=[CH:14][CH:13]=1.[Cl:18][C:19]1[S:23][C:22]([C:24](OCC)=[O:25])=[CH:21][CH:20]=1>CCCCCC.C1COCC1>[Cl:18][C:19]1[S:23][C:22]([C:24](=[O:25])[CH2:11][C:12]2[CH:17]=[CH:16][N:15]=[CH:14][CH:13]=2)=[CH:21][CH:20]=1At 0° C., 64.5 ml of a 1M solution of lithium bis(trimethylsilyl)amide in hexane are added dropwise to a solution of 3.00 g (32.3 mmol) of 4-methylpyridine and 6.77 g (35.5 mmol) of ethyl 5-chlorothiophene-2-carboxylate in 58 ml THF, and the reaction mixture is stirred at 5° C. for 3 h. The resulting precipitate was filtered off, acidified with 6M HCl, filtered again and dried. This gives 2.9 g (35%) of the desired product; 1H-NMR (DMSO-d6): δ=8.53 (d, 2H), 8.09 (d, 1H), 7.40 (d, 1H), 7.34 (d, 2H), 4.39 (s, 2H).
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