Process to obtain benzoxazines to be used for the synthesis of ofloxazine, levofloxazine and derivatives

• Main Authors: JOSE LUIS GARCIA RUANO, JUAN CARLOS CARRETERO GONZALVEZ, MERCEDES VICIOSO SANCHEZ
• Format: Patent
• Language: English
• Published: 12.12.1996
• Edition: 6
• Subjects: ACYCLIC OR CARBOCYCLIC COMPOUNDS; CHEMISTRY; HETEROCYCLIC COMPOUNDS; HUMAN NECESSITIES; HYGIENE; MEDICAL OR VETERINARY SCIENCE; METALLURGY; ORGANIC CHEMISTRY; PREPARATIONS FOR MEDICAL, DENTAL, OR TOILET PURPOSES; SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS ORMEDICINAL PREPARATIONS

Process for obtaining benzoxazines useful for the synthesis of ofloxacin, levofloxacin and derivatives thereof. The benzoxazines (I) wherein Xb is halogen and R1 is H, alkyl or alkylene up to 6 C atoms or aryl, may be obtained by cyclazation of a compound having the formula (II) by reaction with triphenylphosphin and azodicarboxylate of ethyl. The compounds of formula (II) may be obtained by reaction of a compound (III) with an appropriate epoxy. By using the appropriate chiral epoxy, the enantiomerically desired intermediate may be obtained, and consequently it is possible to selectively obtain the desired final product with the appropriate enantiomer form without having to go through a resolution step. The compounds (I) are valuable and key intermediates for the synthesis of antimicrobial agents such as floxacin and levofloxacin.