发明授权
US5459269A 14-halo-camptothecins 失效
14-halo-喜树碱

14-halo-camptothecins
摘要:
A method of making racemic DE ring intermediates for the synthesis of camptothecin and camptothecin analogs employing novel intermediates of Formula (XX) and (XXI): ##STR1## wherein R.sub.20 is loweralkyl, R is loweralkyl, Y is H or halogen, and R.sub.21 is loweralkoxy; as precursors to the DE ring intermediate.The present invention also provides a camptothecin analog of Formula (I-A): ##STR2## wherein: Hal is a halogen;and the remainder of the variables are as defined in the specification.Additionally, other novel compounds useful in the preparation of the compounds of Formula (I-A) and methods of producing compounds of (I-A) are also provided.
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