Sodium Iodide → 1-Tert-butoxycarbonylamino-2-(2-cyano-ethyl)-cyclopropanecarboxylic acid methyl ester

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To 1-tert-butoxycarbonylamino-2 (2-methanesulfonyloxy-1-ethyl)-cyclopropanecarboxylic acid methyl ester (400 mg, 1.19 mmol) from example 109 in DMF (6 mL) was added NaCN (350 mg, 7.14 mmol) and NaI (178 mg, 1.19 mmol). The reaction mixture was heated at 80° C. for 2 h then diluted with EtOAc and washed with water and brine. The organic layer was dried over sodium sulfate, filtered, and concentrated. The crude product was purified by column chromatography on silica (20→50% EtOAc/Hexanes) to afford 1-tert-butoxycarbonylamino-2-(2-cyano-ethyl)-cyclopropanecarboxylic acid methyl ester (297 mg, 93%). 1H NMR (300 MHz, CDCl3): δ 5.13 (br s, 1H), 2.44 (m, 2H), 2.05 (m, 2H), 1.70-1.53 (m, 1H), 1.53-1.37 (m, 4H) 1.45 (s, 9H). LCMS found 290.9 [M+Na]+. To this intermediate (297 mg, 1.10 mmol) in CH2Cl2 (2 mL) was added 4N HCl in dioxanes (2 mL). Ater stirring at room temperature for 2 h the reaction was concentrated to afford 225 mg (100%) of the HCl salt of 1-amino-2-(2-cyano-ethyl)-cyclopropanecarboxylic acid methyl ester, which was used in the next step without further purification.

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