bromination, Pd-catalyzed cyanation, and Sandmeyer diazotization/chlorination. This protocol eliminated the hazardous POCl3 of previous synthetic methods and offered a better yield (48%) which was 1.3-fold higher than a recently published procedure. From intermediate 8, the subsequent nucleophilic fluorination, nitrile hydration and hydroxyl substitution efficiently afforded the target product. Another
SUBSTITUTED PYRAZINO[2,3-D]ISOOXAZOLES AS INTERMEDIATES FOR THE SYNTHESIS OF SUBSTITUTED PYRAZINECARBOXAMIDES
申请人:FUJIFILM Corporation
公开号:US20150051396A1
公开(公告)日:2015-02-19
The object of the present invention is to provide a compound which is useful as a production intermediate of pyrazine carboxamide derivative such as 6-fluoro-3-hydroxy-2-pyrazine carboxamide. The present invention provides a pyrazino[2,3-d]isoxazole derivative represented by the formula (I):
wherein X represents a halogen atom, a hydroxyl group or a sulfamoyloxy group, and Y represents —C(═O)R or —CN; wherein R represents a hydrogen atom, an alkoxy group an aryloxy group, an alkyl group, an aryl group or an amino group.