ASIAN JOURNAL OF CHEMISTRY ASIAN JOURNAL OF CHEMISTRY http://dx.doi.org/10.14233/ajchem.2015.18011 INTRODUCTION Benzodiazepines, from the pharmacological standpoint, are very interesting molecules. Numerous studies have demonstrated anxiolytic effect on the human nervous system. They are used in the therapeutic field 1 and have important biological activities, particularly the 1,4- and 1,5-benzodi- azepines 2 . Benzodiazepines are also used as anticonvulsant agents 3 , anti-inflammatory and analgesic 4 , antidepressive of the central nervous system 5 and antibacterial 6 . For instance, Valium (diazepam) is marketed as a sedative and noveril (dibenzepin) as an antidepressive. The strategy of using benzo- diazepines essentially depends on the knowledge of their pharmacokinetics that can take advantage of their "qualities" but also to avoid some of their "side effects". In addition, benzo- diazepines are the most powerful anticonvulsant substances known so far: they are able of antagonize, common amongst animal, convulsions induced by a wide variety of chemical substances e.g., isoniazid, picrotoxin, strychnine, pentetrazole. On the other hand, they are less effective in protecting seizures due to electric shock 7 . Synthesis of 1,5-benzodiazepines structures were made from different lactones, such as tetronic acid, 4-hydroxy coumarin, demidone and dehydroacetic acid 8 . It therefore seemed interesting to carry on further research by investigating the reactivity of the dehydroacetic acid and its derivatives which are susceptible to serve as starting material for the synthesis of other heterocyclic compounds such as benzodi- Synthesis of Novel Heterocyclic Compounds Containing 1,5-Benzodiazepine B.E. MISSAOUI 1,2,* , M.R. OUAHRANI 1,2 , Y. KOUADRI 1,2 , F. CHEBROUK 3 and N. GHERRAF 4 1 Laboratoire de Chimie Organique, Université KASDI Merbah, Ouargla, Algéria 2 Laboratoire VPRS Université KASDI Merbah, Ouargla, Algéria 3 Centre de Recherche Scientifique et Technique en Analyses Physico-chimiques (CRAPC), BP 248, Alger 16004, Algéria 4 Laboratoire des Ressources Naturelles et Aménagement des milieux Sensibles, Université Larbi ben M'hidi, Oum Elbouaghi, Algeria *Corresponding author: Fax: +213 32 424213; Tel: +213 559103485; E-mail: hadadberini@yahoo.com Received: 15 May 2014; Accepted: 7 October 2014; Published online: 17 March 2015; AJC-16987 The purpose of this work is the development of a synthetic pathway that allows access to heterocyclic compounds containing the 1,5- benzodiazepines. The dehydroacetic acid has been widely studied as a starting material for the synthesis of natural products that exhibit interesting pharmacological properties. In the present work, we describe an easy and cost effective access way to new products 1,5- benzodiazepines involving a pyranic residue. All synthesized products were subjected to IR, 1 H NMR and mass spectra studies. Keywords: Dehydroacetic acid, 1,5-Benzodiazepine. azepines whose basic cores are known for their pharmaco- logical effects. Moreover, 1,5-benzodiazepine type compounds are particularly active on the central nervous system 9 and anticon- vulsants 10 , antiinflammatory, analgesics 11 and antibacterial 12 . The present work is focused on the use of dehydroacetic acid and its derivatives in heterocyclic synthesis. We report in this paper the synthesis of new molecules susceptible to present valuable pharmacological properties namely 1.5-benzodiazepine. The synthesis approach we adopted involves, in one hand, the opening of pyranic ring by binucleophiles reagents such as 2-amino-3-benzyloxypyridine and on the other hand, the action of hydrazine hydrate on pyridopyrimidine. Finally we obtain pyrano-1,5-benzodiazepine (10) by the condensation reaction of o-phenylenediamines substituted on the cyna- moyles from the dehydroacetic acid. EXPERIMENTAL 1 H NMR spectra were performed on spectrometer Bruker AC 200 MHz and 300 MHz. Chemical shifts are given in ppm relative to TMS (internal reference). The 13 C NMR spectra were made in J modulated on a spectrometer Bruker AC 200 and 300 MHz. Infrared spectra were recorded on a Perkin Elmer 225 network spectrophotometer, compounds being in solid suspension in Nujol. The results are given in cm -1 . Mass spectra were performed on a Nermag R10-10C spectrometer with the ionization mode by electronic impact to 70 EV and/ or by chemical ionization by NH3. Melting points were taken on using a Köfler bench. Asian Journal of Chemistry; Vol. 27, No. 6 (2015), 2175-2177