Ultrasound Assisted 1,4-diazabicyclo[2.2.2] Octaniumdiacetate Multicomponent Synthesis of Benzodiazepines: A Novel, Highly Efficient and Green Protocol

Abstract

A simple and efficient method is presented for the synthesis of benzodiazepines through the multicomponent reaction of o-phenylenediamine, various aldehydes and 5,5-dimethylcyclohexane-1,3-dione (dimedone) in the presence of the acidic bis ionic liquid 1,4-diazabicyclo[2.2.2]octanium diacetate under ultrasound irradiation. The ionic liquid used is recoverable and reusable. This procedure is simple and environmentally friendly, and offers easy work-up, mild conditions and excellent yield in a short reaction time. All of the synthesized compounds were characterized by IR, 1 H NMR, mass spectrometry and elemental analysis.

Greener route for microwave enhanced syntheses of bioactive 1,5‐benzodiazepines using heterogeneous calcium ferrite/graphene oxide nanocomposite as a novel and sustainable catalyst

“…Taking into account existing literature , an attempt has been made to propose a plausible mechanism for the formation of 2,3‐dihydro‐1,5‐benzodiazepine derivative via reaction between 4‐substituted acetophenone, benzaldehyde and o ‐phenylene diamine in the presence of calcium ferrite/graphene oxide (CF/GO) as nanocatalyst. The heterogeneous (CF/GO) catalyst activates the carbonyl group of aldehyde to form a transition complex [A] and also promotes enolisation of acetopheneone to produce an active enol [B].…”

CHAPTER 8. Sustainable Activation of Chemical Substrates Under Sonochemical Conditions

“…[Insert Table X 74 . The reaction under silent conditions and at 90 °C afforded the products in higher reaction times and lower yields.…”

Ultrasound for Drug Synthesis: A Green Approach

“…Unfortunately, the compounds tested did not show strong anti-amebic and antibacterial activities. 1-b]thiazoles are important molecules that exhibit a wide variety of biological activities and have potential uses as antidiabetics [99], antifungals [100], and antibiotics [101], and against age-related diseases [102]. Tetrazolo[1,5-a]quinolones [103] and imidazo[2,1-b]thiazoles [100,104] are traditionally synthesized under harsh conditions requiring toxic chemicals, high temperatures, or expensive catalysts, and have a limited substrate scope.…”

“…The ultrasonic bath used f = 35 kHz. Adapted from Shelke et al [98].Similarly, Fekri et al[99] prepared 1,4-diazepin derivatives under ultrasonic irradiation and solventless conditions using an ionic liquid as a catalyst, synthesizing DABCO-diacetate under microwave irradiation. Various parameters were optimized by reacting 4-nitrobenzaldehyde, o-phenyldiamine, and dimedone.…”