Efficient TCT-catalyzed Synthesis of 1,5-Benzodiazepine Derivatives under Mild Conditions

Abstract

2,4,6-Trichloro-1,3,5-triazine (TCT) efficiently catalyzed the condensation reactions between 1,2-diamines and various enolizable ketones to afford 1,5-benzodiazepines in good to excellent yields. Simple and mild reaction conditions, the use of a cheap catalyst and easy workup and isolation are notable features of this method.

Microwave-Assisted, Solvent Free Preparation of 1,5-Benzodiazepine Derivatives Using Nanomagnetic-Supported Sulfonic Acid as a Recyclable and Heterogeneous Catalyst

“…We also carried out synthesis of 3a using various other iron oxide catalysts to compare the catalytic activity of prepared nanoγ-Fe 2 O 3 -SO 3 H as catalyst under solvent-free conditions. The results are shown in Table 2 [11][12][13][14]. However, we used 0.05g of bulk-Fe 2 O 3 -SO 3 H to investigate effect of -SO 3 H group in synthesis of benzodiazepine, this reaction showed good performance of respective diazepine during 2h (entry 15).…”

“…4 Thus, due to the wide applications of benzodiazepine derivatives in medicine and industry, and in organic reactions, there is an imperative need to develop new methodology for the synthesis of these compounds. Various methods for the preparation of benzodiazepines are reported in the literature nine of which [5][6][7][8][9][10][11][12][13] are listed in Table 2. However, many of these methods have some limitations such as low to poor yields, tedious work-up procedures, hazardous and expensive reagents and solvents, and relatively long reaction times.…”

Erbium Salts as Non-Toxic Catalysts Compatible with Alternative Reaction Media

“…Consequently, the development of expedient synthetic approaches to access new BZD scaffolds has attracted significant attention in the discovery of biologically active compounds. Compounds with a 1,5-benzodiazepine scaffold have recently received growing attention because of their pharmacological properties [35,36]. A greater therapeutic potential and lower incidence of side effects were described for 1,5-BZDs when compared to 1,4-BZDs.…”

Phenylboronic acid catalysed synthesis of 1,5-benzodiazepines via cyclocondensation of o-phenylenediamine and ketones

“…[7][8][9][10] In general, cyclocondensation of o-phenylenediamines with carbonyl compounds is one of the conventional synthetic methods for the synthesis of 1,5-benzodiazepine derivatives. 11 A variety of catalysts, such as CeCl 3 -NaI/SiO 2 , 12 SmI 2 , 13 YbCl 3 , 14 MgO/POCl 3 , 15 zeolites, 16 Ga(OTf) 3 , 17 Amberlyst-21-Yb(OPf) 3 , 18 Ag 3 PW 12 O 40 , 19 boric acid, 20 fluorous aqueous emulsion 21 FeAlP-550, 22 iodine, 23 Ytterbium perfluorooctanesulphonate [Yb(OPf) 3 ], 24 2,4,6-Trichloro-1,3,5-triazine 25 and multicite solid catalyst 26 have been utilized for this synthesis. However, these protocols are related with some disadvantages like hazardous reaction condition, extended reaction time and also use of harmful catalyst and organic solvent.…”