| 摘要 |
<p>PURPOSE: To obtain a protected aminothiazolylacetic acid derivative useful for introducing 2-(2-aminothiazol-4-yl)-2-alkenoyl, etc., into a cephem skeleton and protecting an amino group with a protecting group having properties capable of suppressing adverse reaction on an amino group, being stable to various reactions and capable of eliminating in mild conditions. CONSTITUTION: The compound of formula I [A is N or methine; R<1> and R<2> are each H, a lower alkyl or (substituted) aryl; R<3> is a lower (halogenated) alkoxy, triphenylmethoxy, a lower alkyl or an acyloxy; R<4> is a halogen, OH, a lower alkoxy or a (substituted) amino] or its salt, e.g. 2-(2-dimethylamino- methylideneaminothiazol-4-yl)-2-methoxyiminoacetic acid chloride. This compound of formula I is obtained by reacting a compound of formula II with a compound of formula III (X is a halogen).</p> |
