A compound of formula (1) or a salt thereof:
wherein R1 is a carboxy or a protected carboxy; R2 is a lower alkoxy or a higher alkoxy; A1 is a divalent aromatic ring, a divalent heterocyclic group or a divalent cyclo(lower)alkane; and A2 a divalent aromatic ring, a divalent heterocyclic group or a divalent cyclo(lower)alkane; is prepared by reacting a compound of formula (III) or a salt thereof with acid ammonium salt:
wherein R1, R2, A1 and A2 are each as defined above; to give a compound of formula (II) or a salt thereof which is further reacted with a salt of hydroxylamine:
wherein R1, R2, A1 and A2 are each as defined above.
化合物公式为(1)或其盐:
其中,R1为羧基或受保护的羧基;R2为较低的烷氧基或较高的烷氧基;A1为二价芳香环、二价杂环基团或二价环(较低)烷基;A2为二价芳香环、二价杂环基团或二价环(较低)烷基。通过将公式(III)或其盐与酸
铵盐反应,制备得到公式(II)或其盐,其中R1、R2、A1和A2如上所定义。随后,将公式(II)或其盐与
羟胺盐反应,其中R1、R2、A1和A2如上所定义。