Diisopropylethylamine → 5-Pyrimidinecarboxamide, 4-amino-2-(ethylthio)-N-methoxy-N-methyl-

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Reaction Steps

To a solution of 4-amino-2-ethylsulfanyl-pyrimidine-5-carboxylic acid (1.00 g, 5.40 mmol, Sigma) in dimethylformamide were added O-benzotriazol-1-yl-N,N,N′,N′-tetramethyluronium hexafluorophosphate (3.06 g, 8.1 mmol, Aldrich), 1-hydroxy-benzotriazole hydrate (1.09 g, 8.1 mmol, Aldrich) followed by diisopropylethylamine (3.94 g, 29.7 mmol) at 0° C. After stirring for 10–15 minutes, N,O-dimethyl-hydroxylamine. HCl (790 mg, 8.1 mmol, Aldrich) was added. The reaction was stirred at 0° C. to room temperature for 2 hours and then diluted with ethyl acetate and water. The aqueous layer was separated and extracted with ethyl acetate. The combined organic extracts were washed with brine, dried and concentrated. The crude product was purified on silica gel with 1:1 hexane/ethyl acetate to give 4-amino-2-ethylsulfanyl-pyrimidine-5-carboxylic acid methoxy-methyl-amide as a white solid (1.189 g, 98% yield). HRMS, observed: 242.0836; Calcd for M+: 242.0837

Provenance & Evidence