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US 4,309,354 AGranted
Chromone derivatives
AssigneeEisai Co., Ltd.
InventorsSeiichiro Nomoto, Hironori Ikuta, Yoshimasa Machida, Shigeto Negi, Isao Sugiyama, Hiroshi Yamauchi, Kenro Nakatsuka, Isao Saito
Life of this patent
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Abstract
New chromone derivatives having the formula: ##STR1## wherein A represents a hydrogen atom, a halogen atom or a hydroxyl group, and R.sub.1 represents a lower alkyl or a chloro-substituted lower alkyl group. The derivatives are useful intermediates for synthesis of cephem derivatives as antibacterial drugs.
Claims4
Chromone derivatives having the formula:
- ##STR22## wherein A represents a hydrogen atom, a halogen atom or a hydroxyl group, and R.sub.1 represents a lower alkyl or a chloro-substituted lower alkyl group.
Dependencies are inferred from the claim text.