On The Synthesis of Pyridinylthiobarbituric Acids

2002 ◽  
Vol 55 (4) ◽  
pp. 287 ◽  
Author(s):  
L. W. Deady ◽  
D. Ganame ◽  
N. H. Quazi ◽  
S. D. Zanatta
Keyword(s):  
Trifluoroacetic Acid ◽  
Efficient Synthesis ◽  
Thiourea Derivatives

The reaction of N-(pyridin-3-yl) and -4-yl thiourea derivatives with malonyl dichloride in trifluoroacetic acid is shown to be an efficient synthesis of the corresponding thiobarbituric acids. The pyridin-2-yl analogue cleaved and produced, instead, 2-hydroxy-4H-pyrido[1,2a]pyrimidin-4-one.

A Facile and Efficient Synthesis of bis(Imidazo[1,2-a]pyridin-3-yl)methane and vinyl derivatives

2021 ◽  
Vol 18 ◽  
Author(s):  
D.E. Prasada Rao ◽  
M. David Raju ◽  
J. Surendra ◽  
A. Vasu Babu ◽  
P. Eswaraiah ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Trifluoroacetic Acid ◽  
Methyl Chloride ◽  
The Novel ◽  
Synthetic Route ◽  
Efficient Synthesis ◽  
Vinyl Derivatives

An efficient synthetic route for the novel bis-imdizo[1,2-a]pyridine-3-yl)methane (2a-k) derivatives have been developed using acetic acid and two drops of trifluoroacetic acid at 40-45oC, resulting in 60-72% yields. An attempt to synthesize bis(Imidazo[1,2-a]pyridin-3-yl)methyl chloride derivatives by the reaction between two moles of imidazo[1,2-a]pyridine, one mole of chloroacetaldehyde in acetic acid, and two drops of trifluoroacetic acid was not successful, instead underwent dehydrohalogenation to yield vinyl derivatives (4a-d).

Trifluoroacetic acid-mediated intramolecular formal N-H insertion reactions with amino-α-diazoketones: a facile and efficient synthesis of optically pure pyrrolidinones and piperidinones

2000 ◽  
Vol 78 (6) ◽  
pp. 800-808 ◽  
Author(s):  
Hua Yang ◽  
Valdas Jurkauskas ◽  
Nicole Mackintosh ◽  
Tobias Mogren ◽  
Corey RJ Stephenson ◽  
...  
Keyword(s):  
Amino Acid ◽  
Trifluoroacetic Acid ◽  
Efficient Synthesis ◽  
Insertion Reactions ◽  
C And N ◽  
Optically Pure

Trifluoroacetic acid (TFA) was found to promote intramolecular formal N-H insertion reactions. Upon treatment with TFA, optically pure N-Boc-β'-amino-α-diazoketones (5a-c) and N-Boc-γ'-amino-α-diazoketones (10a-d) can be converted, with retention of chirality, into pyrrolidinones (11a-c) and piperidinones (12a-d), respectively, with concomitant removal of the Boc group, in good to excellent yields.Key words: α-diazoketone, amino acid, pyrrolidinone, piperidinone, N-H insertion.

Intramolecular Oxidative Coupling of Aromatic Compounds. VI. An Efficient Synthesis of Some Dibenzocyclooctene Lignans

1994 ◽  
Vol 47 (5) ◽  
pp. 937 ◽  
Author(s):  
AR Carroll ◽  
WC Taylor
Keyword(s):  
Trans Isomer ◽  
Trifluoroacetic Acid ◽  
Aromatic Compounds ◽  
Oxidative Coupling ◽  
Good Yield ◽  
Reductive Coupling ◽  
Efficient Synthesis

The 1,4-diaryl-2,3-dimethylbutanes (4) and (5) were readily prepared by reductive coupling of an arylacetone precursor followed by hydrogenation. Intramolecular oxidative coupling (dichlorodicyanobenzoquinone/trifluoroacetic acid) gave dibenzocyclooctene derivatives in good yield. (�)-Deoxyschizandrin and the corresponding trans isomer, existing in two distinct conformations, were prepared.

Simple and efficient synthesis of novel glycosyl thiourea derivatives as potential antitumor agents

2008 ◽  
Vol 43 (12) ◽  
pp. 2778-2783 ◽  
Author(s):  
Zhang Shusheng ◽  
Zhan Tianrong ◽  
Cheng Kun ◽  
Xia Youfeng ◽  
Yang Bo
Keyword(s):  
Antitumor Agents ◽  
Efficient Synthesis ◽  
Thiourea Derivatives ◽  
Potential Antitumor

A concise and efficient synthesis of amino-substituted (1H-benzo[d]imidazol-1-yl)pyrimidine hybrids: synthetic sequence and the molecular and supramolecular structures of six examples

2019 ◽  
Vol 75 (10) ◽  
pp. 1405-1416
Author(s):  
Daniel E. Vicentes ◽  
Ricaurte Rodríguez ◽  
Patricia Ochoa ◽  
Justo Cobo ◽  
Christopher Glidewell
Keyword(s):  
Hydrogen Bonds ◽  
Ethyl Acetate ◽  
Trifluoroacetic Acid ◽  
Three Dimensional ◽  
Supramolecular Assembly ◽  
Oxidative Cleavage ◽  
Supramolecular Structures ◽  
Two Dimensional ◽  
Efficient Synthesis ◽  
Synthetic Sequence

A concise and efficient synthesis of a series of amino-substituted benzimidazole–pyrimidine hybrids has been developed, starting from the readily available N 4-(2-aminophenyl)-6-methoxy-5-nitrosopyrimidine-2,4-diamine. In each of N 5-benzyl-6-methoxy-4-(2-phenyl-1H-benzo[d]imidazol-1-yl)pyrimidine-2,5-diamine, C25H22N6O, (I), 6-methoxy-N 5-(4-methoxybenzyl)-4-[2-(4-methoxyphenyl)-1H-benzo[d]imidazol-1-yl]pyrimidine-2,5-diamine, C27H26N6O3, (III), 6-methoxy-N 5-(4-nitrobenzyl)-4-[2-(4-nitrophenyl)-1H-benzo[d]imidazol-1-yl]pyrimidine-2,5-diamine, C25H20N8O5, (IV), the molecules are linked into three-dimensional framework structures, using different combinations of N—H...N, N—H...O, C—H...O, C—H...N and C—H...π hydrogen bonds in each case. Oxidative cleavage of 6-methoxy-N 5-(4-methylbenzyl)-4-[2-(4-methylphenyl)-1H-benzo[d]imidazol-1-yl]pyrimidine-2,5-diamine, (II), with diiodine gave 6-methoxy-4-[2-(4-methylphenyl)-1H-benzo[d]imidazol-1-yl]pyrimidine-2,5-diamine, which crystallized as a monohydrate, C19H18N6O·H2O, (V), and reaction of (V) with trifluoroacetic acid gave two isomeric products, namely N-{5-amino-6-methoxy-6-[2-(4-methylphenyl)-1H-benzo[d]imidazol-1-yl]pyrimidin-2-yl}-2,2,2-trifluoroacetamide, which crystallized as an ethyl acetate monosolvate, C21H17F3N6O2·C4H8O2, (VI), and N-{2-amino-6-methoxy-4-[2-(4-methylphenyl)-1H-benzo[d]imidazol-1-yl]pyrimidin-5-yl}-2,2,2-trifluoroacetamide, which crystallized as a methanol monosolvate, C21H17F3N6O2·CH4O, (VIIa). For each of (V), (VI) and (VIIa), the supramolecular assembly is two-dimensional, based on different combinations of O—H...N, N—H...O, N—H...N, C—H...O and C—H...π hydrogen bonds in each case. Comparisons are made with some related structures.

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