D. Jung, Ju-hyun Song, Yong-hwan Kim
2007
Citations
0
Influential Citations
11
Citations
Journal
Bulletin of The Korean Chemical Society
Abstract
Benzodiazepines are interesting compounds because of their pharmacological properties. Many members of this family are, in fact, nowadays widely used as tranquilizing and anticonvulsant agents. Although the first benzodiazepine was introduced as a drug nearly 30 years ago, the research in this area is still very active and is directed towards the synthesis of compounds of enhanced pharmacological activity. Some benzodiazepine derivatives are also used in industry, such as in photography (as dyes for acrylic fibers), and also as anti-inflammatory agents. 1H-1,5Benzodiazepines are used as starting materials for the preparation of some fused ring benzodiazepine derivatives, such as triaxol and oxadiazol. Despite their wide range of pharmacological activity, industrial and synthetic application, the synthesis of 1H-1,5-benzodiazepines has received little attention. As a part of research program related to the synthetic study of pharmacologically interesting benzodiazepine compounds, herein we now report the synthesis of 1H-1,5-benzodiazepine derivatives with heteroaromatic ketones (2-acetylfuran 2a, 2-acetylthiophene 2b, 2-acetylpyridine 2c, 3-acetylpyridine 2d, and 4-acetylpyridine 2e) by using conc-HCl, SiO2, or polyphosphoric acid (PPA) (Scheme 1). Specially we report synthesis of quinoxaline derivatives with phenylenediamine 1a and acetylpyridines 2c, 2e in aqueous 10% conc-HCl solution (Scheme 2). Moreover we describe the structural analysis of 7-chloro2,2,4-trimethyl-2,3-dihydro-1H-1,5-benzodiazepine 3f and 8-chloro-2,2,4-trimethyl-2,3-dihydro-1H-1,5-benzodiazepine 3g synthesized by 4-chloro-1,2-phenylenediamine 1b with acetone. Earlier we reported the synthesis of 2,4,4,-trimethyl-3H-5hydro-1,5-benzodiazepine and 2,4-diphenyl-4-methyl-3H-5hydro-1,5-benzodiazepine by using various reagents instead of PPA. When 1a was treated with 2a in the presence of PPA at 4045 °C for 5 h, a yellow crystalline solid, 3a was isolated