Diisopropylethylamine → 5-{[4-Cyano-1-(2-trimethylsilanyl-ethoxymethyl)-1H-imidazole-2-carbonyl]-amino}-6-(4,4-dimethyl-cyclohex-1-enyl)-3',4',5',6'-tetrahydro-2'H-[2,4']bipyridinyl-1'-carboxylic acid tert-butyl ester

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Reaction Steps

A solution of 150 mg (0.389 mmol) 5-amino-6-(4,4-dimethyl-cyclohex-1-enyl)-3′,4′,5′,6′-tetrahydro-2′H-[2,4′]bipyridinyl-1′-carboxylic acid tert-butyl ester (as prepared in the previous step) in 15 mL of CH2Cl2 was treated with 131 mg (0.428 mmol) of 4-cyano-1-(2-trimethylsilanyl-ethoxymethyl)-1H-imidazole-2-carboxylate potassium salt (as prepared in Example 3, step (b)), 272 mg (0.584 mmol) PyBroP, and 203 μL (1.17 mmol) DIEA at room temperature for 3 h. The mixture was diluted with CH2Cl2 and washed with saturated aqueous NaHCO3. The organic layer was dried over MgSO4 and concentrated in vacuo. Chromatography of the residue on a 50-g silica Varian MegaBond Elut column with 50% EtOAc-hexanes afforded 215 mg (87%) of the title compound as a white solid. Mass spectrum (ESI, m/z): Calcd. for C34H50N6O4Si, 635.4 (M+H), found 635.3.

Provenance & Evidence