Diisopropylethylamine → 2-methoxy-6-methylsulfanyl-4-trifluoromethyl-N-(1,4,8-trioxa-spiro[4.5]dec-6-yl)-benzamide

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Reaction Steps

2-Methoxy-6-methylsulfanyl-4-trifluoromethyl-benzoic acid (intermediate A, 400 mg, 1.5 mmol) was dissolved in 10 mL dimethylformamide. N,N-Diisopropyl ethyl amine (505 mg, 3.9 mmol) and O-(7-azabenzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate (571 mg, 1.5 mmol) were added. After 10 minutes of stirring at room temperature 1,4,8-trioxaspiro[4,5]decan-6-amine (CAS 1068523-26-1) (359 mg, 2.2 mmol) was added. The reaction mixture was stirred at room temperature overnight. The solvent was evaporated off. The residue was taken up in 2N sodium carbonate solution and ethyl acetate and was extracted three times with ethyl acetate. The combined organic phases were dried on sodium sulfate, filtered and evaporated. Purification of the residue by flash chromatography on silica gel (heptane/ethyl acetate/triethylamine 1:0:0→10:10:1) yielded 2-methoxy-6-methylsulfanyl-4-trifluoromethyl-N-(1,4,8-trioxa-spiro[4.5]dec-6-yl)-benzamide as a white solid (462 mg, 75%), MS: m/e=408.2 [(M+H)+].

Provenance & Evidence