Novel synthesis of 2-naphthol Mannich bases and their NMR behaviour

2006 ◽  
Vol 84 (6) ◽  
pp. 843-853 ◽  
Author(s):  
Amitabh Jha ◽  
Nawal K Paul ◽  
Smriti Trikha ◽  
T Stanley Cameron
Keyword(s):  
Variable Temperature ◽  
Mannich Bases ◽  
One Pot ◽  
X Ray ◽  
X Ray Crystallography ◽  
Microwave Assisted ◽  
Extensive Variable ◽  
Solvent Free Conditions ◽  
Aerial Oxidation ◽  
Temperature Variable

A novel two-step procedure involving the formation of 1-arylidene-2-tetralones from 2-tetralone and subsequent Michael addition of a cyclic secondary amine on the alkenone followed by in situ aerial oxidation was developed to produce 2-naphthol Mannich bases. A simple microwave-assisted one-pot synthesis of 2-naphthol Mannich bases was also carried out under solvent-free conditions from 2-naphthol and corresponding aldehydes and amines in the presence of p-toluenesulfonic acid. The compounds of this series displayed interesting NMR behaviour. Extensive variable-temperature NMR investigations, including HSQC experiments, are herein reported. NMR results on the conformation in solution phase were found to be consistent with the X-ray crystal structure in the solid state.Key words: Mannich bases, microwave-assisted Mannich reaction, temperature-variable NMR spectroscopy, NMR dynamics, X-ray crystallography.

scholarly journals Microwave-assisted efficient one-pot synthesis of N 2-(tetrazol-5-yl)-6-aryl/heteroaryl-5,6-dihydro-1,3,5-triazine-2,4-diamines

2020 ◽  
Vol 16 ◽  
pp. 1706-1712
Author(s):  
Moustafa Sherief Moustafa ◽  
Ramadan Ahmed Mekheimer ◽  
Saleh Mohammed Al-Mousawi ◽  
Mohamed Abd-Elmonem ◽  
Hesham El-Zorba ◽  
...  
Keyword(s):  
Microwave Heating ◽  
Aromatic Aldehydes ◽  
One Pot ◽  
X Ray ◽  
X Ray Crystallography ◽  
Microwave Assisted ◽  
One Pot Synthesis ◽  
High Yields

An efficient one-pot synthesis of N 2-(tetrazol-5-yl)-6-aryl/heteroaryl-1,3,5-triazine-2,4-diamine derivatives was developed by reacting 5-amino-1,2,3,4-tetrazole with aromatic aldehydes and cyanamide in pyridine under controlled microwave heating with high yields. X-ray crystallography confirmed the structure of the obtained products.

scholarly journals Peroxidative Oxidation of Alkanes and Alcohols under Mild Conditions by Di- and Tetranuclear Copper (II) Complexes of Bis (2-Hydroxybenzylidene) Isophthalohydrazide

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2699 ◽  
Author(s):  
Manas Sutradhar ◽  
Elisabete Alegria ◽  
M. Guedes da Silva ◽  
Cai-Ming Liu ◽  
Armando Pombeiro
Keyword(s):  
Variable Temperature ◽  
Product Yield ◽  
Antiferromagnetic Coupling ◽  
Oxidation Reactions ◽  
X Ray ◽  
X Ray Crystallography ◽  
Mild Conditions ◽  
Microwave Assisted ◽  
Oxidation Of Alcohols ◽  
Cyclohexyl Hydroperoxide

Bis(2-hydroxybenzylidene)isophthalohydrazide (H4L) has been used to synthesize the dinuclear [Cu2(1κNO2:2κN′O′2-H2L)(NO3)2(H2O)2] (1) and the tetranuclear [Cu4(μ-1κNO2:2κN′O2-H2L)2(μ-NO3)2(H2O)4]·2C2H5OH (2) complexes. The solvent plays an important role in determining the ligand behaviour in the syntheses of the complexes. An ethanol-acetonitrile mixture of solvents favours partials enolization in the case of 2. Both complexes have been characterized by elemental analysis, infrared radiation (IR), single crystal X-ray crystallography and electrochemical methods. The variable temperature magnetic susceptibility measurements of 2 show strong antiferromagnetic coupling between the central nitrato-bridged Cu (II) ions. The catalytic activity of both 1 and 2 has been screened toward the solvent-free microwave-assisted oxidation of alcohols and the peroxidative oxidation of alkanes under mild conditions. Complex 1 exhibits the highest activity for both oxidation reactions, leading selectively to a maximum product yield of 99% (for the 1-phenylethanol oxidation after 1 h without any additive) and 13% (for the cyclohexane oxidation to cyclohexyl hydroperoxide, cyclohexanol and cyclohexanone after 3 h).

scholarly journals Microwave-assisted efficient one-pot synthesis of N 2-(tetrazol-5-yl)-6-aryl/heteroaryl-2,3-dihydro-1,3,5-triazine-2,4-diamines

2020 ◽  
Author(s):  
Moustafa Moustafa ◽  
Ramadan Mekheimer ◽  
Saleh Al-Mousawi ◽  
Mohamed Abd-Elmonem ◽  
Hesham El-Zorba ◽  
...  
Keyword(s):  
Microwave Heating ◽  
Aromatic Aldehydes ◽  
One Pot ◽  
X Ray ◽  
X Ray Crystallography ◽  
Microwave Assisted ◽  
One Pot Synthesis ◽  
High Yields

An efficient one-pot synthesis of N 2-(tetrazol-5-yl)-6-aryl/heteroaryl-1,3,5-triazine-2,4-diamine derivatives was developed by reacting 5-amino-1,2,3,4-tetrazole with aromatic aldehydes and cyanamide in pyridine under controlled microwave heating with high yields. X-ray crystallography confirmed the structure of obtained products.  

Microwave-Assisted Efficient, One-Pot, Three-Component Synthesis of 3,5-Disubstituted 1,2,4-Oxadiazoles under Solvent-Free Conditions.

ChemInform ◽  
2006 ◽  
Vol 37 (32) ◽  
Author(s):  
Mehdi Adib ◽  
Amin Haghighat Jahromi ◽  
Narjes Tavoosi ◽  
Mohammad Mahdavi ◽  
Hamid Reza Bijanzadeh
Keyword(s):  
Solvent Free ◽  
One Pot ◽  
Microwave Assisted ◽  
Solvent Free Conditions

scholarly journals A new one-pot three-component synthesis of 4-aryl-6-cycloamino-1,3,5-triazin-2-amines under microwave irradiation

Synthesis ◽  
2021 ◽  
Author(s):  
Muhammad Syafiq Bin Shahari ◽  
Ahmad Junaid ◽  
Edward R. T. Tiekink ◽  
Anton V. Dolzhenko
Keyword(s):  
Microwave Irradiation ◽  
Aromatic Aldehydes ◽  
Antileukemic Activity ◽  
One Pot ◽  
Biological Screening ◽  
X Ray ◽  
X Ray Crystallography ◽  
Cyclic Amines ◽  
Three Component Reaction ◽  
Fast Synthesis

A new method for the fast synthesis of diverse 4-aryl-6-cycloamino-1,3,5-triazin-2-amines was developed. The synthesis is performed under microwave irradiation in a one-pot manner from cyanoguanidine, aromatic aldehydes, and cyclic amines. Their three-component reaction in the presence of hydrochloric acid produced dihydrotriazines, which were then converted (without isolation) to the targeted compounds via aromatic dehydrogenation in the presence of alkali. The reaction tolerated various aromatic aldehydes (including heterocyclic) and cyclic amines. Crystal structures of two representative 4-aryl-6-morpholino-1,3,5-triazin-2-amines were established by X-ray crystallography. The results of preliminary biological screening identified potent antileukemic activity for 6-(3,4-dihydroisoquinolin-2(1<i>H</i>)-yl)-4-phenyl-1,3,5-triazin-2-amine.

Zirconium complexes of a cyclopentadienyl-amido ligand with a pendant amine donor via amine and alkane elimination

1996 ◽  
Vol 74 (9) ◽  
pp. 1696-1703 ◽  
Author(s):  
Ying Mu ◽  
Warren E. Piers ◽  
Donald C. MacQuarrie ◽  
Michael J. Zaworotko
Keyword(s):  
Lewis Acids ◽  
Methyl Chloride ◽  
Monoclinic Space Group ◽  
One Pot ◽  
Amido Complexes ◽  
X Ray ◽  
X Ray Crystallography ◽  
Zirconium Complexes ◽  
Alkane Elimination

Zirconium complexes of the multidentate ligand CpHNMeSiN(H)R (SiNR = -SiMe2N-t-butyl; NMe = -CH2CH2NMe2, 1) were prepared and characterized via amine and alkane elimination procedures. Reaction of 1 with Zr(NMe2)4 gave a mixture of bis-amido complexes 2 in which the ligand was 1,2 and 1,3 substituted. This mixture was converted to the analogous dichlorides 3 using Me2NH•HCl and 1,3-3 was purified at this stage; alternatively, 1,3-3 was obtained in one pot from 1 and Zr(NMe2)4 in ≈70% yield. Conversion of 1,3-3 to dimethyl compound (CpNMeSiNR)Zr(CH3)2, 1,3-4, was accomplished via reaction of the dichloride with methyllithium; methide abstraction with the Lewis acids B(C6F5)3 and [Ph3C]+[B(C6F5)4]− generated the cationic alkyls [(CpNMeSiNR)Zr(CH3)]+[R′B(C6F5)3]− (R′ = CH3, 6a; C6F6, 6b), which were characterized by NMR spectroscopy. Zirconium complexes containing 1 ligated as its 1,2 isomer were obtained from alkane elimination reactions between 1 and in situ prepared RnZrCl4−n (R = CH3, n = 3; R = CH2SiMe3, n = 2). 1,2-3 and the methyl chloride complex 1,2-(CpNMeSiNR)Zr(CH3)Cl, 5, were obtained in 18 and 30% yield, respectively. Complex 5 was characterized by X-ray crystallography (monoclinic, space group P21/a, a = 9.6951(10) Å, b = 14.3794(16) Å, c = 14.364(3) Å, V = 1990.3(5) Å3, Z = 4, R = 0.046, Rw = 0.041.) Key words: amine elimination, Cp-amido, zirconium complexes.

Synthesis, characterization and crystal structures of novel fluorinated di(thiazolyl)benzene derivatives

2019 ◽  
Vol 6 (6) ◽  
pp. 780-790 ◽  
Author(s):  
Maciej Barłóg ◽  
Ihor Kulai ◽  
Xiaozhou Ji ◽  
Nattamai Bhuvanesh ◽  
Somnath Dey ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Benzene Derivatives ◽  
Stille Coupling ◽  
X Ray ◽  
X Ray Crystallography ◽  
Microwave Assisted

A series of 11 novel fluorinated and non-fluorinated di(thiazolyl)benzenes have been synthesized via microwave assisted Stille coupling and characterized using X-ray crystallography.

Silane catecholates: versatile tools for self-assembled dynamic covalent bond chemistry

2019 ◽  
Vol 55 (43) ◽  
pp. 6066-6069 ◽  
Author(s):  
Yoshiteru Kawakami ◽  
Tsuyoshi Ogishima ◽  
Tomoki Kawara ◽  
Shota Yamauchi ◽  
Kazuhiko Okamoto ◽  
...  
Keyword(s):  
Covalent Bond ◽  
One Pot ◽  
X Ray ◽  
X Ray Crystallography ◽  
Self Assembled

Shape-persistent macrocycles and 3D nanocages have been prepared in one-pot under MeCN-promoted dynamic covalent bond conditions starting from silane catecholates, whose structures were confirmed by X-ray crystallography.

Catalyst-Free Synthesis of Diastereomerically Pure 3-Sulfonyl­azetidin-2-ones via Microwave-Assisted Tandem Wolff Rearrangement–Staudinger Cycloaddition

Synthesis ◽  
2020 ◽  
Author(s):  
Mikhail Krasavin ◽  
Judith Synofzik ◽  
Olga Bakulina ◽  
Olga Balabas ◽  
Dmitry Dar’in
Keyword(s):  
Drug Design ◽  
Single Crystal ◽  
Wolff Rearrangement ◽  
X Ray ◽  
Design And Optimization ◽  
X Ray Crystallography ◽  
Microwave Assisted ◽  
Catalyst Free ◽  
Relative Stereochemistry ◽  
Wide Range

A wide range of α-diazo-β-ketosulfones have been applied to thermally promoted tandem Wolff rearrangement – Staudinger [2+2] cycloaddition with imines to give polysubstituted β-lactam sulfones. Dia­stereomerically pure syn-diastereomers were obtained in good yields and the relative stereochemistry was confirmed by single-crystal X-ray crystallography. These findings significantly expand the scope of this transformation, in contrast to substantial limitations reported previously. Moreover, this methodology enables flexible exploration of new substitution patterns around the privileged β-lactam core for drug design and optimization.

scholarly journals Cu(II) and Fe(III) Complexes Derived from N-Acetylpyrazine-2-Carbohydrazide as Efficient Catalysts Towards Neat Microwave Assisted Oxidation of Alcohols

Catalysts ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1053 ◽  
Author(s):  
Manas Sutradhar ◽  
Tannistha Roy Barman ◽  
Armando J. L. Pombeiro ◽  
Luísa M. D. R. S. Martins
Keyword(s):  
Catalytic Activity ◽  
Ir Spectroscopy ◽  
Maximum Yield ◽  
Catalytic Efficiency ◽  
Benzyl Alcohols ◽  
X Ray ◽  
X Ray Crystallography ◽  
Microwave Assisted ◽  
Tert Butyl Hydroperoxide ◽  
Oxidation Of Alcohols

The mononuclear Cu(II) complex [Cu((kNN′O-HL)(H2O)2] (1) was synthesized using N-acetylpyrazine-2-carbohydrazide (H2L) and characterized by elemental analysis, IR spectroscopy, ESI-MS and single crystal X-ray crystallography. Two Fe(III) complexes derived from the same ligand viz, mononuclear [Fe((kNN′O-HL)Cl2] (2) and the binuclear [Fe(kNN′O-HL)Cl(μ-OMe)]2 (3) (synthesized as reported earlier), were also used in this study. The catalytic activity of these three complexes (1–3) was examined towards the oxidation of alcohols using tert-butyl hydroperoxide (TBHP) as oxidising agent under solvent-free microwave irradiation conditions. Primary and secondary benzyl alcohols (benzyl alcohol and 1-phenylethanol), and secondary aliphatic alcohols (cyclohexanol) were used as model substrates for this study. A comparison of their catalytic efficiency was performed. Complex 1 exhibited the highest activity in the presence of TEMPO as promoter for the oxidation of 1-phenylethanol with a maximum yield of 91.3% of acetophenone.

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