Two non zwitterionic analogues of fluoroquinolone drugs, viz. 1-ethyl-7-piperidino-8-fluoroquinol-4- one-3-carboxylic acid and 1-ethyl-7-piperidino-6,8-difluoroquinol-4-one-3-carboxylic acids have been synthesized and their photochemistry has been investigated. Both compound undergo photoheterolysis of the C8 F bond generating a triplet cation that either inserts into the 1-alkyl chain or is trapped or reduced by external nucleophiles. The reaction is analogous to that observed with the corresponding (zwitterionic) 7-piperazino derivatives, but the quantum yield is ca five times lower. This supports the rationalization that in the latter case assistance to defluorination by the N+ H bond has a determining role.
Photochemistry of some non zwitterionic fluoroquinolones
DICHIARANTE, VALENTINA;PRETALI, LUCA;FASANI, ELISA;ALBINI, ANGELO
2013-01-01
Abstract
Two non zwitterionic analogues of fluoroquinolone drugs, viz. 1-ethyl-7-piperidino-8-fluoroquinol-4- one-3-carboxylic acid and 1-ethyl-7-piperidino-6,8-difluoroquinol-4-one-3-carboxylic acids have been synthesized and their photochemistry has been investigated. Both compound undergo photoheterolysis of the C8 F bond generating a triplet cation that either inserts into the 1-alkyl chain or is trapped or reduced by external nucleophiles. The reaction is analogous to that observed with the corresponding (zwitterionic) 7-piperazino derivatives, but the quantum yield is ca five times lower. This supports the rationalization that in the latter case assistance to defluorination by the N+ H bond has a determining role.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
