Synthesis and Preliminary Bioassays of Some Bis -1,3 - Benzoxazines

Four previously synthesized (R =-F,-F,-CI,-Br,-l) and one new (R=-H) 3,3' -ethylene-bis(3,4-dihydro-6R-2H-1,3-benzoxa2Íne) were preliminary tested for insecticidal activity against M. domestica (Díptera) and C. cary (Lepidoptera) larvae. Under laboratory conditions no toxic action was observed. All larvae continued development and pupated successfully but internal or external malformations were observed in adults when hatched. INTRODUCTION 1,3-Benzoxazines (BOAs) have long been recognized for their wide range of biological activities, includlng fungistatic, bacteriostatic and insecticidal activities (1). A method for the preparation of N-substituted-3,4-dihydro-2H-1,3-benzoxazines by a Mannich type condensation of appropriate phenol with primary amines and two equivalents of formaldehyde was developed by Burke (2). Using this method with substantial modifications which will be published elsewhere we REVISTA COLOMBIANA DE QUÍMICA VOL. 19 No. 2 (1990) 67 have synthesized a variety of 3,3 elhylene-bis(3^4.dihydro-6-substituted-2H1,3-benzoxazine) (R-BlSBOAs). In the present work we report the preparation of compounds la-e searching for enhanced biological activity. These compounds were tested against a dipterous and a lepidopterous larvae. The synthesis of compounds I be has been reported earlier (3) (4) while to the best of our knowledge, la was unknown so far. On the other hand, it is very important to mention that the National Cáncer Institute (USA) has requested us to provide them with additional material of compound Ib for AIDS antiviral evaluation.