Microwave Assisted Aromatic Nucleophilic Substitution Reaction Under Solventless Condition

Rebeiro, Geeta L.; Khadilkar, Bhushan M.

doi:10.1081/scc-120018702

Cited by 10 publications

(2 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A solventless synthesis of p -nitrodiphenyl ethers by aromatic nucleophilic substitution reaction of p -NCB with different phenoxides has been reported . Mil’to et al , have studied the kinetics of p -NCB reactions with substituted phenolates.…”

Section: Introductionmentioning

confidence: 99%

Ionic Liquid as Catalyst for Solid−Liquid Phase Transfer Catalyzed Synthesis of p-Nitrodiphenyl Ether

Yadav

Motirale

2008

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

The novelties of solid−liquid phase transfer catalyzed synthesis of p-nitrodiphenyl ether from p-nitrochlorobenzene and potassium phenoxide were studied in detail with ionic liquids as phase transfer catalysts among others. Tetradecyl(trihexyl)phosphonium bromide was found to be the best catalyst leading to 100% selectivity toward the desired product p-nitrodiphenyl ether. Ionic liquids offer excellent conversions and selectivity, stability at high temperatures, and reusability in this reaction. A mathematical model was developed to study the kinetics of the reaction and used to extract both the rate constant and ion-exchange equilibrium constant. The contribution of the uncatalyzed reaction was also considered in this model. The activation energy and Gibb’s free energy for a combined ion exchange were also calculated. Microwave irradiation was also employed as an effective alternative to conventional heating.

show abstract

Section: Introductionmentioning

confidence: 99%

Ionic Liquid as Catalyst for Solid−Liquid Phase Transfer Catalyzed Synthesis of p-Nitrodiphenyl Ether

Yadav

Motirale

2008

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

show abstract

“…Although a slightly lower, comparable yields of the benzothiazines were obtained and the methodology is also affordable even for the cyclisation of hindered ortho-substituted acrylates (3f, 3i). In view that nucleophilic aromatic substitution (S N Ar) reactions have not been explored much under microwave irradiation conditions [12], this work represents a new contribution to the knowledge of the application of microwave synthesis to achieve this goal efficiently in short reaction times. EXPERIMENTAL Melting points were determined in a Fischer-Johns micro hotstage apparatus and are uncorrected.…”

mentioning

confidence: 99%

A microwave induced cyclisation of α‐phenylsulfonyl‐enaminoacrylates for the preparation of 4‐aryl‐4H‐1,4‐benzothiazine 1,1‐dioxide derivatives

López

Salazar

Rebollo

et al. 2005

Journal of Heterocyclic Chem

View full text Add to dashboard Cite

Several 4-aryl-4H-1,4-benzothiazine 1,1-dioxide derivatives have been prepared in good yields by microwave promoted cyclisation of α-phenylsulfonyl-enaminoacrylate intermediates in basic media. Benzothiazines were obtained without the use of a catalyst in short reaction times.J. Heterocyclic Chem., 42, 1007Chem., 42, (2005.During the course of our research toward the synthesis of novel 4-aryl-4H-1,4-benzothiazine 1,1-dioxide derivatives [1-3], we decided to explore some new alternatives for the crucial cyclisation step of the α-phenylsulfonyl enaminoacrylate intermediates to the corresponding benzothiazines. Despite this kind of cyclisation is relatively easy for their isostere counterpart α-phenylcarbonyl enaminoacrylates for the synthesis of 1-arylquinolones by the widely employed Groche's methodology [4], it was not achieved in high yields for the preparation of 4-aryl substituted 1,4-benzothiazines unless a 5% silver nitrate was used as a catalyst (Scheme 1) [2]. The silver nitrate, may complex the chlorine atom of the aromatic ring lowering the energy of the transition state of the aromatic substitution bringing the reaction to completion in high yields. Recently, a great interest in microwave promoted reactions has emerged in organic synthesis [5], it has been used for the preparation of heterocycles [5-10] and valuable organic intermediates in short reaction times without the use of costly reagents and catalysts. This available technology has led us to test microwave irradiation for the synthesis of organofluorine aromatic amides [11] and the cyclisation of enaminoacrylates to 4-aryl-4H-1,4-benzothiazines (4 a-i) without the aid of catalyst (Scheme 2), standard conditions were established varying the microwave power source and the reaction time (Table 1). Our results show that microwave irradiation is a good alternative for the cyclisation step instead of use of a catalyst. Although a slightly lower, comparable yields of the benzothiazines were obtained and the methodology is also affordable even for the cyclisation of hindered ortho-substituted acrylates (3f, 3i). In view that nucleophilic aromatic substitution (S N Ar) reactions have not been explored much under microwave irradiation conditions [12], this work represents a new contribution to the knowledge of the application of microwave synthesis to achieve this goal efficiently in short reaction times.

show abstract

A Versatile and Efficient Ligand for Copper‐Catalyzed Formation of CN, CO, and PC Bonds: Pyrrolidine‐2‐Phosphonic Acid Phenyl Monoester

Rao

Jin

et al. 2006

Chemistry A European J

361

View full text Add to dashboard Cite

A new and readily available bidentate ligand, namely, pyrrolidine-2-phosphonic acid phenyl monoester (PPAPM), has been developed for the copper-catalyzed formation of C-N, C-O, and P-C bonds, and various N-, O-, and P-arylation products were synthesized in good to excellent yields by using the CuI/PPAPM catalyst system. Addition of the PPAPM ligand greatly increases the reactivity of the copper catalyst, and the resulting versatile and efficient catalyst system is of widespread and practical application in cross-coupling reactions.

show abstract

Microwave Assisted Aromatic Nucleophilic Substitution Reaction Under Solventless Condition

Cited by 10 publications

References 3 publications

Ionic Liquid as Catalyst for Solid−Liquid Phase Transfer Catalyzed Synthesis of p-Nitrodiphenyl Ether

Ionic Liquid as Catalyst for Solid−Liquid Phase Transfer Catalyzed Synthesis of p-Nitrodiphenyl Ether

A microwave induced cyclisation of α‐phenylsulfonyl‐enaminoacrylates for the preparation of 4‐aryl‐4H‐1,4‐benzothiazine 1,1‐dioxide derivatives

A Versatile and Efficient Ligand for Copper‐Catalyzed Formation of CN, CO, and PC Bonds: Pyrrolidine‐2‐Phosphonic Acid Phenyl Monoester

Contact Info

Product

Resources

About