Pavel Pazdera

FT-IR, FT-Raman spectroscopy and computational study of (E)-4-((anthracen-9-ylmethylene)amino)-N-carbamimidoylbenzene sulfonamide.

The infrared and Raman spectra of (E)-4-((anthracen-9-ylmethylene)amino)-N-carbamimidoylbenzene sulfonamide have been recorded and analysed. Geometry and harmonic vibrational wavenumbers were calculated theoretically using Gaussian03 set of quantum chemistry codes. The data obtained from vibrational wavenumber calculations are used to assign vibrational bands found in infrared and Raman spectra of the studied molecule. The red-shift of the NH stretching band in the infrared spectrum from the computed wavenumber indicates the weakening of the NH bond. The NH stretching band has split into a doublet in the IR spectrum owing to the Davydov coupling between neighbouring units. The geometrical parameters of the title compound are in agreement with the reported similar derivatives. The calculated first hyperpolarizability is comparable with the reported value of similar structures and may be an attractive object for further studies on non-linear optics. The important thermodynamical parameters are also reported.

2-(Substituted phenyl)amino analogs of 1-methoxyspirobrassinol methyl ether: Synthesis and anticancer activity

New analogs of indole phytoalexin 1-methoxyspirobrassinol methyl ether have been designed by replacement of its 2-methoxy group with 2-(substituted phenyl)amino group. Synthesized by spirocyclization methodology, trans- and cis-diastereoisomers of target compounds were isolated and evaluated as potential anticancer and antimicrobial agents. Their molecular geometries were refined by ab initio minimizations. Pharmacophore modeling and QSAR studies were performed in order to correlate their molecular structure and biological activity.

Synthesis of N-(2-cyanophenyl)chloromethanimidoyl chloride

N-(2-Cyanophenyl)chloromethanimidoyl chloride (3) was prepared from 2-isothiocyanatobenzonitrile by the reaction with sulfuryl chloride or gaseous chlorine in an inert solvent. It was found that N-(2-cyanophenyl)chloromethanimidothioic chloride (2) and bis[N-(cyanophenyl)chloromethanimidoyl] sulfide (7) are intermediates of this reaction. The chloride 3 was obtained also by a three-component one-pot reaction of N-(2-cyanophenyl)-formamide in the present of thionyl chloride and sulfuryl chloride. (2-Cyanophenyl)-(1-{[(2-cyanophenyl)-imino]methoxy}methylidene)ammonium chloride (6) was detected as a by-product of this reaction. Identity of all reaction products was confirmed by GC-MS, FTIR, 1H and 13C NMR spectroscopy.

One-pot Syntheses of Fused Quinazolines by Reaction of N-(2-Cyanophenyl)chloromethanimidoyl Chloride. I. A New Synthesis of 1,3-Oxazolo- and 1,3-Oxazino[2,3-b]quinazolines

Abstract: 12 H -Benzo[1,3]oxazolo[2,3-b]quinazolin-12-imine ( 5a ), 9-chloro-12 H -benzo[1,3]oxazolo[2,3-b]quinazolin-12-imine ( 5b ), 2,3-dihydro-5 H -[1,3]oxazolo[2,3-b]quinazolin-5-imine ( 5c ), 2,3-dihydro-3,3-dimethyl-5 H -[1,3]oxazolo[2,3-b]quinazolin-5-imine ( 5d ) and 3,4--dihydro-2 H ,6 H -[1,3]oxazino[2,3-b]quinazolin-6-imine ( 5e ) weresynthesized in a one-pot reaction of N-(2-cyanophenyl)chloromethanimidoyl chloride ( 1 )with 2-aminophenols, 2-aminoethanol, and 3-aminopropanol in the presence of a base. Thecourse of the reaction was controlled by the temperature and the amount of base used. N -(2-Cyanophenyl)-(2-hydroxyanilino)methanimidoyl chloride ( 3a ), 2-chloro-3-(2-hydroxy-phenyl)-3,4-dihydroquinazolin-4-imine ( 4a ) and 6-imino-2 H , 3 H , 4 H , 6 H , 11 H -1,3-oxazino[2,3-b]-5-quinazolinium chloride ( 6 ) were identified as intermediates of the one-pot process. Keywords: N -(2-cyanophenyl)chloromethanimidoyl chloride, 1,3-oxazolo[2,3-b]-quinazoline, 1,3-oxazino[2,3-b]quinazoline, methanimidoyl chloride, fused quinazolines,

Synthesis of Heterocyclic Skeletons by the Reaction of N1-(2-Cyanophenyl)-benzimidoyl Chloride with Thioamides

The reaction of N-(2-cyanophenyl)benzimidoyl chloride with reagents containing a thioamide moiety, i.e. thioacetamide, benzylthiourea, symmetrical dialkyl- and diarylthioureas gave different cyclic products: 3,1-benzothiazine, 1,3,5-benzotriazocine and quinazoline. The reaction pathways of prepared compounds are discussed.

One-Pot Quinazolin-4-yl-thiourea Synthesis via N-(2-Cyanophenyl) benzimidoyl isothiocyanate

1-substituted-3-(2-phenylquinazolin-4-yl) thioureas (7) were produced by an intramolecular cycloaddition reaction of 1-substitued-3-[(2-cyanophenyl- imino)phenylmethyl] thioureas (3). These compounds in turn were prepared by the reaction of N-(2-cyanophenyl)benzimidoyl isothiocyanate (2) with primary amines. The structures of products 7 were confirmed by FTIR, 1H-NMR, 13C-NMR, mass spectroscopy and X-ray crystallography.

One-Pot Quinazolin-4-ylidenethiourea Synthesis via N-(2- Cyanophenyl)benzimidoyl isothiocyanate

1,1-Disubstituted-3-(2-phenyl-3H-quinazolin-4-ylidene)thioureas (8) were synthesized in a one pot reaction of N-(2-cyanophenyl)benzimidoyl isothicyanate (3) with secondary amines. The products underwent transamination reactions. Compounds 8a-8g were identified by FTIR, 1H-NMR, 13C-NMR, mass spectroscopy and X-ray crystallography.

Photoisomerization of Ethyl 2-(3-Acylselenoureido)thiophene- 3-carboxylates and Their Benzoanalogues

Synthesis, isomerisation and structure elucidation of the title compounds 1–6 and its isomers 7–12 by FTIR, 1H, 13C, 15N, 77Se NMR spectroscopy is reported. Ethyl 2–(3–acylselenoureido)thiophene–3–carboxylates and their benzoanalogues (where acyl is benzoyl and pivaloyl) were prepared by addition of ethyl 2–aminothiophene–3–carboxylates and ethyl 2–aminobenzoate on benzoyl– or pivaloylisoselenocyanate in acetone solution. An isomerization of 1–6 to the corresponding 3–acylisoselenoureas 7–12 was obtained. The isomerisation proceeds either by irradiation with light (340–400 nm) or in the case of benzoylderivatives 1, 3, 5 by treatment with acetic acid. On the other hand the acid action in the pivaloyl set inhibited this isomerisation and evoked the retroisomerisation reaction of 8, 10, 12 to 2, 4, 6. Thermal analyses showed that isomerisation can be initiated also by heating. These changes proceed in the solid phase as an exothermic process at an elevated temperature but always below the temperature of melting. The structure 2 was supported by X–ray analysis. Molecular design of 2 and 8 was modeled during application of ab initio quantum chemistry calculation.

Acid-base properties, FT-IR, FT-Raman spectroscopy and computational study of 1-(pyrid-4-yl)piperazine.

We report the vibrational spectral analysis was carried out using FT-IR and FT-Raman spectroscopy for 1-(pyrid-4-yl)piperazine (PyPi). Single crystals of PyPi suitable for X-ray structural analysis were obtained. The acid-base properties are also reported. PyPi supported on a weak acid cation-exchanger in the single protonated form and this system can be used efficiently as the solid supported analogue of 4-N,N-dimethyl-aminopyridine. The complete vibrational assignments of wavenumbers were made on the basis of potential energy distribution. The HOMO and LUMO analysis is used to determine the charge transfer within the molecule and with the molecular electrostatic potential map was applied for the reactivity assessment of PyPi molecule toward proton, electrophiles and nucleopholes as well. The stability of the molecule arising from hyper-conjugative interaction and charge delocalization has been analyzed using NBO analysis. The calculated first hyperpolarizability of PyPi is 17.46 times that of urea.

New Heterocyclic Organophosphorus-Sulfur-Nitrogen Compounds, Syntheses and Structures.

The new compound C10H6P(S)[NSi(CH3)3]2P(S) (3) which contains a P2N2 heterocycle has been prepared in an 8% yield by partial thermal decomposition of 1-{[N,N-bis(trimethylsilyl)acetamidinium]sulfido}-3-(trimethyls ilylamino)-1H,3H,1lambda5,3lambda5-naphth[1, 8a,8-cd][1,2,6]thiadiphosphinine-1,3-dithione [CH3C{NHSi(CH3)3}2]+ [C10H6P(S)(NHSiMe3) SP(S)2] (2). Reaction of 2 with potassium hydroxide in acetonitrile gives the completely desilylated product [CH3C(NH2)2]+ [C10H6P(S)(NH2)SP(S)2] (4). The structures of the new compounds 3 and 4 were elucidated by FTIR and nmr spectroscopic methods and by x-ray structure analyses.