Solvent-Free one pot synthesis of benzo-[b]-1,4-diazepines using reusable sulfamic acid catalyst

Abstract

Į-ȕ-Unsaturated carbonyl compounds on condensation with o-phenylenediamine in the presence of catalyst sulfamic acid under solvent free conditions, resulted in the formation of corresponding benzo-[b]-1,4-diazepines in excellent yields.

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“…TLC was used to monitor the completion of the reaction; the structures of products were assessed by interpretation of IR and NMR spectra obtained. The spectroscopic data of IR and 1 H-NMR are in agreement with the structure of fused 1, 4-diazepine derivatives 3,4,6,7,8,9,10 .…”

Sulfamic Acid as Versatile Green Catalyst Used For Synthetic Organic Chemistry: A Comprehensive Update

“…Also, Sarda et al [96] used sulfamic acid in an efficient and mild protocol for the synthesis of benzo-[b]-1,4-diazepines (Scheme 34). The operationally simple protocol provided excellent yields of the products, and the catalyst was recycled and reused for several times.…”

“…Also, Sarda et al [96] . used sulfamic acid in an efficient and mild protocol for the synthesis of benzo‐[b]‐1,4‐diazepines (Scheme 34).…”

Chalcone derived benzoheterodiazepines for medicinal applications: A Two‐pot and one‐pot synthetic approach

“…Solvent-free condensation is an eco-friendly reaction to avoid hazardous, volatile, and toxic organic solvents usages [135]. Numerous catalysts have been used such as Zn/K-10, Ag 3 PW 12 O 40 , sulfamic acid [136], SbCl 3 -Al 2 O 3 [137], oxalic acid [135], for the synthesis of benzodiazepine (14). Among these catalysts, sulfamic acid is reported as an efficient catalyst with a shorter reaction time (1.5-2 h) and gave a high yield of product (85%-95%) [136].…”

“…Numerous catalysts have been used such as Zn/K-10, Ag 3 PW 12 O 40 , sulfamic acid [136], SbCl 3 -Al 2 O 3 [137], oxalic acid [135], for the synthesis of benzodiazepine (14). Among these catalysts, sulfamic acid is reported as an efficient catalyst with a shorter reaction time (1.5-2 h) and gave a high yield of product (85%-95%) [136]. A catalyst derived from graphite oxide has also been reported in the synthesis of 1,5-benzodiazepines ( 15) by heating at 80 C (30 min) under solvent-free conditions to produce good to excellent yields.…”