An efficient method for the synthesis of 1,5-benzodiazepine derivatives under microwave irradiation without solvent

Pozarentzi, Minothora; Stephanidou‐Stephanatou, Julia; Tsoleridis, Constantinos A.

doi:10.1016/s0040-4039(02)00115-6

Cited by 162 publications

(59 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Herein, we report the synthesis of pyridodiazepines and benzodiazepines by reacting heteroaryl/aryl diamines with b-aryl vinyl ketones in solid phase without using any catalyst and solvent under microwave irradiation (Scheme I). Previously microwave reactions for the synthesis of benzodiazepines from o-phenylenediamines with various ketones are carried out using Al 2 O 3 /P 2 O 5 [8] or AcOH [18] catalyst. But in the present procedure benzodiazepines are synthesized in quite good yield without any catalyst.…”

Section: Resultsmentioning

confidence: 99%

“…So far the different methods, which have been developed for the synthesis of benzodiazepines include the condensation of 1,2-diamines with a,b-unsaturated carbonyl compounds [6], ketones and b-haloketones [7] in the presence of Al 2 O 3 -P 2 O 5 [8], SbCl 3 -Al 2 O 3 [9], polyphosphoroic acid-SiO 2 [10], Yb(Otf) 3 [11], BF 3 -etherate [12], MgO-POCl 3 [13], Zn [L-proline] 2 [14], Amberlyst-15 [15], NaBH 4 [16], ionic liquid [17], and AcOH [18]. Recently, alum [KAl(SO 4 ) 2 Á12H 2 O] is also used as a catalyst for the synthesis of benzodiazepines [19].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

New access to the one‐pot solvent‐free synthesis of 4,5‐dihydro‐pyrido[2,3‐b][1,4]diazepines and 2,3‐dihydro‐benzo[b][1,4]diazepines by microwave irradiation

Goswami

Hazra

Jana

2009

Journal of Heterocyclic Chem

View full text Add to dashboard Cite

magnified imageA series of diversely substituted pyridodiazepines and benzodiazepines have been synthesized in solvent and catalyst free microwave condition from aryl/heteroaryl diamines and β‐aryl vinyl ketones. The yields of the reactions varied with the substituents attached to the aryl/heteroaryl diamines. This common protocol is equally effective for the synthesis of pyridodiazepines and benzodiazepines with pharmacological interest, though in case of pyridodiazepines required time is comparatively higher than benzodiazepines. J. Heterocyclic Chem., (2009).

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

New access to the one‐pot solvent‐free synthesis of 4,5‐dihydro‐pyrido[2,3‐b][1,4]diazepines and 2,3‐dihydro‐benzo[b][1,4]diazepines by microwave irradiation

Goswami

Hazra

Jana

2009

Journal of Heterocyclic Chem

View full text Add to dashboard Cite

show abstract

“…Although the rearranged intermediates have not been directly detected in the EDTA decomposition, some potential fragments can still be proposed. It is reported that compound 1 could be prepared by condensation of o-PDA with 4-methyl-3-penten-2-one, 25 acetone, [26][27][28][29][30][31] acetonedicarboxylic acid, 32 or 2, 4, 4-trichloro-2-metylpentane 33 under different conditions ( Figure 5). These facts suggest that the rearranged intermediates might be one or some of these reactants.…”

Section: Resultsmentioning

confidence: 99%

“…[38][39][40][41][42] Several methods for preparing these compounds have been reported in the literature. [25][26][27][28][29][30][31][32] To our knowledge, the formation of the 1,5-benzodiazepine skeleton by the reaction of EDTA with o-PDA in strong acidic medium has not been reported so far. Although this reaction may not be an economic route for the preparation of compound 1, it helps us to sketch a new potential thermal decomposition mechanism for EDTA.…”

Section: Resultsmentioning

confidence: 99%

Thermal decomposition of ethylenediaminetetraacetic acid in the presence of 1,2-phenylenediamine and hydrochloric acid

Chen¹,

Gao²,

Wang³

2006

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

Considerando os produtos de reação do ácido etilenodiaminotetraacético (EDTA) com 1,2-fenilenodiamina (o-PDA), um novo processo para a decomposição térmica do EDTA é proposto. O meio ácido forte e a presença de o-PDA facilitam a decomposição de EDTA, como evidenciado pela temperatura relativamente baixa de reação. Em adição aos passos descritos na literatura, um processo de rearranjo está presente na reação de decomposição. Os intermediários rearranjados condensam com o-PDA, formando um inesperado composto biologicamente ativo 2,2,4-trimetil-3H-5-hidro-1,5-benzodiazepina, proporcionando a possibilidade de explorar um mecanismo de decomposição alternativo para este quelante amplamente utilizado.Based on the reaction products of ethylenediaminetetraacetic acid (EDTA) with 1,2-phenylenediamine (o-PDA), a novel thermal decomposition pathway of EDTA is proposed. The strong acidic medium and the presence of o-PDA facilitate the decomposition of EDTA as evidenced by the relatively lower reaction temperature. In addition to the steps described in literatures, rearrangement process is involved in the decomposition reaction. The rearranged intermediates condense with o-PDA, forming an unexpected biologically active compound 2,2,4-trimethyl-3H-5-hydro-1,5-benzodiazepine, thus provides the possibility to explore an alternative decomposition mechanism for this widely used chelator.Keywords: ethylenediaminetetraacetic acid, heterocycle, reaction mechanism, thermal decomposition, thermochemistry IntroductionEthylenediaminetetraacetic acid (EDTA) is one of the most extensively used chelating agents in chemistry, biochemistry, medicine, environmental sciences, and paper industry.1-6 As a scavenger for metal oxides or a stabilizer for metal ions, EDTA is also used at elevated temperatures to prevent scale deposits in high-pressure boilers or nuclear reactors owing to its thermal stability. Nevertheless, the behaviour of EDTA in waste water effluents 8,9 and natural aquatic systems 10 has incurred lots of threats to the natural environment. EDTA not only increases the total nitrogen contents, but also remobilizes most toxic heavy metals from solid matter into water solution and thus extends their biological life cycles. 11Hence, great attention has been paid to the study on decomposition mechanism 12-17 and treatment technique 18 for this aminopolycarboxylic acid complexing agent. Both EDTA and its disodium salt are stable to heat even at 423 K.19 EDTA begins to decompose at about 463 K and nearly 50% breaks down at 483 K in the presence of metal ions. 12 Stepwise decarboxylations and hydrolysis procedures of the ethylene C-N link of EDTA have been suggested by earlier researchers. 13,14 As shown in Figure 1, the decomposition mode may differ greatly with temperature changes. 14,15 Other factors such as acidity and reaction medium can also influence the decomposition of EDTA. For example, Vol. 17, No. 5, 2006 when ammonia was used as a reaction medium and reactant in a high pH system, both ammonolysis and hydrolysis of EDTA oc...

show abstract

“…One of the most efficient methods for their preparation is the domino reaction of o-phenylenediamine (o-PDA) with ketones, [3] α,β-unsaturated carbonyl compounds, or β-haloketones. [4] Catalysts such as BF 3 ·OEt 2 , [5] NaBH 4 , [6] Yb(OTf) 3 , [7] Ga(OTf) 3 , [8] polyphosphoric acid, [9] nitrobenzoic acid, [10] multisite solid catalysts, [11] as well as ionic liquids, [12] and microwave irradiation assisted methods [13] have been employed to improve the yield under mild reaction conditions. Series of functionalized 1,5-benzodiazepine derivatives were obtained as racemates, whereas the enantioselective synthesis of these scaffolds has not been achieved.…”

Section: Introductionmentioning

confidence: 99%

Enantioselective Synthesis of 2‐Substituted‐1,5‐Benzodiazepines through Domino Reaction of o‐Phenylenediamine and Chalcone Derivatives

Feng

Dong

et al. 2011

Eur J Org Chem

View full text Add to dashboard Cite

show abstract

An efficient method for the synthesis of 1,5-benzodiazepine derivatives under microwave irradiation without solvent

Cited by 162 publications

References 21 publications

New access to the one‐pot solvent‐free synthesis of 4,5‐dihydro‐pyrido[2,3‐b][1,4]diazepines and 2,3‐dihydro‐benzo[b][1,4]diazepines by microwave irradiation

New access to the one‐pot solvent‐free synthesis of 4,5‐dihydro‐pyrido[2,3‐b][1,4]diazepines and 2,3‐dihydro‐benzo[b][1,4]diazepines by microwave irradiation

Thermal decomposition of ethylenediaminetetraacetic acid in the presence of 1,2-phenylenediamine and hydrochloric acid

Enantioselective Synthesis of 2‐Substituted‐1,5‐Benzodiazepines through Domino Reaction of o‐Phenylenediamine and Chalcone Derivatives

Contact Info

Product

Resources

About