| 摘要 |
<p>4-(Protected amino)-3-oxo-1-(substituted and unsubstitinted methylene)-1,2-pyrazolidinium ylides are intermediates to 7-substituted bicyclic pyrazolidinone antimicrobials. The intermediates have the formula <CHEM> wherein: R1 and R2 are the same or different and are hydrogen, C1 to C6 alkyl, C1 to C6 substituted alkyl, C7 to C12 arylalkyl, C7 to C12 substituted arylalkyl, phenyl, substituted phenyl, or a group of the formula -COOR5 wherein R5 is C1 to C6 alkyl, C1 to C6 substituted alkyl, C7 to C12 arylalkyl, C7 to C12 substituted arylalkyl, phenyl, substituted phenyl, a carboxy protecting group, or a non-toxic, metabolically-labile ester-forming group; and R3 and R4 are 1) taken together to form a phthalimido group; or 2) either R3 or R4 is hydrogen and the other of R3 or R4 is an amino-protecting group.</p> |
