Hexafluorophosphate → 2-Azido-4-(3-trifluoromethyl-phenyl)-thiazole-5-carboxylic acid amide

Beteiligte Stoffe

Reaktionsschritte

A solution of 2.20 g (7.01 mmole) of 2-azido-4-(3-trifluoromethyl-phenyl)-thiazole-5-carboxylic acid, 38 mL of dimethylformamide, 3.47 g (8.85 mmole) of 1-[bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium, 3-oxide, hexafluorophosphate(1-) (1:1) and 3.75 mL (21.53 mmole) of ethyldiisopropylamine was stirred at room temperature for 23 minutes, then 0.5733 g (10.72 mmole) of ammonium chloride was added. The mixture was stirred for 2.25 hours, then concentrated under reduced pressure and partitioned between 300 mL of ethyl acetate and 75 mL of water. The ethyl acetate layer was washed twice with 60 mL of water, twice with 55 mL of saturated aqueous sodium bicarbonate, once with 50 mL of brine, dried over anhydrous sodium sulfate, filtered, concentrated under reduced pressure. The residue was purified by silica gel chromatography, eluting with ethyl acetate-hexanes (gradient 10:90-100-:0) to give 1.841 g 2-azido-4-(3-trifluoromethyl-phenyl)-thiazole-5-carboxylic acid amide as a light yellow solid.

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