New Preparation of 2-N-Alkyl(aryl)amino-5-methyl-4H-1,3-thiazin-4-ones and 3,4-Dihydro-5-methyl-2,4-dioxo-2H-1,3-thiazine

1993 ◽  
Vol 58 (4) ◽  
pp. 893-901 ◽  
Author(s):  
Dušan Koščík ◽  
Milan Dzurilla ◽  
Peter Kutschy

Addition-cyclization reactions of 3-bromo- and 3-chloro-2-methylpropenoylisothiocyanates with primary and secondary amines and alcohols have been studied. The formed addition products, thioureas, underwent cyclization of heating with ethanolic KOH or in dimethylformamide in the presence of lithium hydride. This method represents a new approach to 2-dialkyl(aryl)amino-5-methyl-4H-1,3-thiazin-4-ones. Addition reactions with alcohols afforded 3,4-dihydro-5-methyl-2,4-dioxo-2H-1,3-thiazine as the sole product. The structure of the synthesized compounds was confirmed by 1H NMR, 13C NMR, IR and mass spectroscopy.

1983 ◽  
Vol 48 (11) ◽  
pp. 3315-3328 ◽  
Author(s):  
Dušan Koščík ◽  
Pavol Kristian ◽  
Jozef Gonda ◽  
Emília Dandárová

Addition reactions of 2-chloronicotinoyl isothiocyanate with primary and secondary amines and subsequent cyclization of intermediate thioureas represent new synthesis of pyrido[3,2-e]thiouracil and pyrido[3,2-e]-thiazine derivatives. 2-Amino-4-oxopyrido[3,2-e]-1,3-thiazines are formed upon heating the reaction components in ethanol, whereas 1-alkyl(aryl)pyrido[3,2-e]-2-thiouracils are products of alkali-catalyzed reaction. In reaction with primary amines the corresponding thioureas were isolated as intermediates, whereas secondary amines reacted directly to give the pyridothiazine derivatives. Structure of the synthesized compounds was confirmed by their 13C NMR and mass spectra; also the IR and 1H NMR spectra are in accord with the suggested formulae.


1987 ◽  
Vol 52 (4) ◽  
pp. 989-994 ◽  
Author(s):  
Milan Dzurilla ◽  
Ondrej Forgáč ◽  
Peter Kutschy ◽  
Pavol Kristian ◽  
Dušan Koščík ◽  
...  

2-Cyanocyclohexylideneacetyl isothiocyanate (II) reacts with sodium hydrogen sulfide to give 1-thia-3-azaspiro[5,5]undecane. Reaction of II with secondary amines afforded 1-thia-3-azaspiro[5,5]undec-2-enes whereas primary aromatic amines gave 1,3-diazaspiro[5,5]undecanes under the same conditions. Both types of reactions proceed via substituted thioureas which were isolated pure only in the case of 4-methylaniline and 4-methoxyaniline. They were cyclized in alkaline medium to the corresponding diazaspiro derivatives. The structure of the synthesized compounds was confirmed by their elemental analyses and IR, 1H NMR, 13C NMR and mass spectroscopy.


1983 ◽  
Vol 48 (12) ◽  
pp. 3426-3432 ◽  
Author(s):  
Dušan Koščík ◽  
Pavol Kristian ◽  
Ondrej Forgáč

New synthesis of pyrido[3,4-e]-1,3-thiazines consisting in reaction of 2,6-dimethyl-4-chloronicotinoyl isothiocyanate with primary or secondary amines, or with benzaldehyde phenylhydrazone, is described. High reactivity of the chlorine atom does not allow isolation of the corresponding thioureas, arising as intermediates, except in the case of the benzylamino derivative. Structure of the products was unequivocally confirmed by their spectral data (IR, UV, 1H NMR, 13C NMR and mass spectra). The synthesized derivatives do not undergo the Dimroth rearrangement.


2015 ◽  
Vol 10 (2) ◽  
pp. 271
Author(s):  
Wei-Guo Li ◽  
He-Qun Wang

<p>A series of novel thiazolidinedione analogues (TZD) were designed and synthesized potent inhibitors of HBV capsid assembly. The synthesis of thiazolidine-2,4-dione derivatives (4a–4o), starting from the condensation of 5-(ethoxymethylene)thiazolidine-2,4-dione (1) with various secondary amines (3) derived from biologically active compounds. The newly synthesized TZD analogues 4a-4o were characterized by <sup>1</sup>H NMR, <sup>13</sup>C NMR, and MS and evaluated for their anti-HBV activity. Most of the compounds inhibited the expression of viral antigens at low concentration. Six compounds, 4g, 4h, 4l, 4m, 4n, and 4o, demonstrated potent inhibition of HBV DNA replication at submicromolar range. Of these five initial hits, compound 4o was the most active when compared with lamivudine.</p><p> </p><p> </p>


1988 ◽  
Vol 43 (2) ◽  
pp. 165-170 ◽  
Author(s):  
Whei Oh Lin ◽  
Maria C. B. V. de Souza ◽  
Helmut G. Alt

The synthesis of trans-1.2-cyclohexanedioxydiacetamides starting with trans-1.2-cyclohexane-diol is described. Eleven of these compounds are characterized by IR, 1H NMR, 13C NMR and mass spectroscopy as well as elemental analyses. Most of these compounds are suitable ionophors for the cations K+ and Ca2+. The coordination sites of these ligands in the 1:2 complexes were determined by IR and NMR spectroscopy


2015 ◽  
Vol 1120-1121 ◽  
pp. 877-881
Author(s):  
Chao Jun He ◽  
Yu Min Yang ◽  
Kong Yang Wu

The biotransformation of 18β-glycyrrhetinic acid by Colletotrichum lini AS3.4486 was investigated. The conversion reaction was carried out for 72h, and the sole product was isolated by column chromatography and elucidated as 7β,15α-dihydroxy-18β-glycyrrhetinic acid by HR-ESI-MS, 1H-NMR , 13C-NMR and single–crystal X-ray diffraction. The crystal of the conversion product belongs to orthorhombic, space group P212121 with 11.828(1), 13.213(2), 19.606(2) Å , V = 3064.0 Å3, Z = 4. This study povides a new method for the synthesis of 7β,15α-dihydroxy-18β-glycyrrhetinic acid.


2012 ◽  
Vol 8 ◽  
pp. 1400-1405 ◽  
Author(s):  
Suri Babu Madasu ◽  
Nagaji Ambabhai Vekariya ◽  
M N V D Hari Kiran ◽  
Badarinadh Gupta ◽  
Aminul Islam ◽  
...  

Eletriptan hydrobromide (1) is a selective serotonin (5-HT1) agonist, used for the acute treatment of the headache phase of migraine attacks. During the manufacture of eletriptan hydrobromide the formation of various impurities were observed and identified by LC–MS. To control the formation of these impurities during the preparation of active pharmaceutical ingredients, the structure of the impurities must be known. Major impurities of the eletriptan hydrobromide synthesis were prepared and characterized by using various spectroscopic techniques, i.e., mass spectroscopy, FTIR , 1H NMR, 13C NMR/DEPT, and further confirmed by co-injection in HPLC. The present study will be of great help in the synthesis of highly pure eletriptan hydrobromide related compounds.


1982 ◽  
Vol 47 (12) ◽  
pp. 3268-3282 ◽  
Author(s):  
Ján Imrich ◽  
Pavol Kristian

Substituted thioureas, obtained by reaction of 3-chloro-3-phenylpropenoyl isothiocyanate with primary aliphatic or aromatic amines, were cyclized to 2-N-alkyl(aryl)amino-6-phenyl-4H-1,3-thiazin-4-ones. The enamine-imine tautomerism was investigated by means of infrared and ultraviolet spectra and also by model substances prepared either by reacting the starting isothiocyanate with secondary amines, or by methylation of 2-N-alkyl(aryl)amino-6-phenyl-4H-1,3-thiazin-4-ones. The structure of the synthesized compounds was corroborated by 1H NMR and electron impact mass spectra. 2-N-Arylamino derivatives dissolved in chloroform exist prevalently an imino form whereas 2-N-alkylamino derivatives is an amino form. Reaction of 3-chloro-3-phenylpropenoyl isothiocyanate with aliphatic thiols gave 2-alkylthio-6-phenyl-4H-1,3-thiazin-4-ones and with sodium hydrosulfide (hydroselenide) 6-phenyl-2-thioxo-2,3-dihydro-4H-1,3-thiazin(selenazin)-4-ones.


Author(s):  
A.M. Shah ◽  
A.J. Rojivadiya

An efficient protocol for the synthesis of imidazo [1,2-a] pyrimidine was developed by using three component one-pot Biginelli synthesis. The synthesized compounds were characterized by spectroscopic techniques like FT-IR, 1H NMR, 13C NMR, and mass spectroscopy.


2012 ◽  
Vol 16 (04) ◽  
pp. 403-412 ◽  
Author(s):  
Charles A. Enow ◽  
Charlene Marais ◽  
Barend C.B. Bezuidenhoudt

A number of novel carbonyl(1,4,8,11,15,18,22,25-octaalkylphthalocyaninato)-ruthenium(II) complexes were prepared by metal insertion with Ru3(CO)12. The new compounds have been characterized by1H NMR,13C NMR, IR, UV-vis and mass spectroscopy. This study demonstrated that this type of complexes and specifically carbonyl(1,4,8,11,15,18,22,25-octahexylphthalo-cyaninato)ruthenium(II) and carbonyl[1,4,8,11,15,18,22,25-octa(2-cyclohexylethyl)phthalocyaninato]-ruthenium(II), exhibit high catalytic activity and stability in the epoxidation of stilbenes with 2,6-dichloropyridine N-oxide as oxidant.


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