反应详情

BOP coupling of (S)-3-cyclohexyl-2-(4-methylsulfonyl-1-oxo-1,3-dihydro-isoindol-2-yl)-propionic acid and regio-isomeric (S)-3-cyclohexyl-2-(7-methylsulfonyl-1-oxo-1,3-dihydro-isoindol-2-yl)-propionic acid (200 mg; 0.55 mmol) and 2-aminopyrazine (88 mg; 0.91 mmol) in a manner similar to that used for the preparation of (S)-3-cyclohexyl-2-(1-oxo-1,3-dihydro-isoindol-2-yl)-N-thiazol-2-yl-propionamide (outlined in Example 9, Step B) provided after flash chromatography (Biotage 40S; eluent: ethyl acetate/methylene chloride, gradient:20% to 60%) a crude mixture that was further purified by reverse phase HPLC (Rainin Dynamax SD-1 instrument) using a gradient of 10% acetonitrile/water/0.1% trifluoroacetic acid to 90% acetonitrile on a C18 column to give 21 mg of (S)-3-Cyclohexyl-2-(4-methylsulfonyl-1-oxo-1,3-dihydro-isoindol-2-yl)-N-pyrazin-2-yl-propionamide: EI-HRMS m/e calcd for C22H24N4O4SNa (M++Na+) 465.1567, found 465.1570 and 13 mg of (S)-3-Cyclohexyl-2-(7-methylsulfonyl-1-oxo-1,3-dihydro-isoindol-2-yl)-N-pyrazin-2-yl-propionamide: EI-HRMS m/e calcd for C22H24N4O4SNa (M++Na+) 465.1567, found 465.1568.