Synthesis of substituted 1,2,3,4-tetrahydroquinoline-4-carboxylic acids

Reduction of some substituted quinoline-4-carboxylic acids was studied. The reduction of 2-alkylquinoline-4-carboxylic acids with Raney nickel in aqueous alkali was stereoselective, and the resulting 2-alkyl-1,2,3,4-tetrahydroquinoline-4-carboxylic acids were individual cis isomers. Original Russian Text ? Yu.A. Zhuravleva, A.V. Zimichev, M.N. Zemtsova, Yu.N. Klimochkin, 2009, published in Zhurnal Organicheskoi Khimii, 2009, Vol. 45, No. 4, pp. 622–625.     

Synthesis of substituted 2-aminoquinoline-3-carboxylic acid amides

Substituted 3-(2-nitrophenyl)-2-cyanoacrylic acid amides were synthesized by the Knoevenagel reaction and were then reduced with iron in acetic acid to the corresponding 2-aminoquinoline-3-carboxylic acid amides.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1515–1517, November, 1988.     

Synthesis and reactions of 8-benzylidene-2-methyl-5,6,7,8-tetrahydroquinoline-3-carboxylic acid arylamides

Arylamides of 8-benzylidene-2-methyl-5,6,7,8-tetrahydroquinoline-3-carboxylic acid were obtained by treating the ethyl ester with dimagnesylamines. An example is given of their conversion to 8-benzylidene-2-styryl-5,6,7,8-tetrahydroquinoline-3-carboxylic acid anilides and subsequent cyclization to 1-oxo-1,2,3,4,6,7,8,9-octa-hydrobenzo[b]-1,6-naphthyridines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 506–508. April, 1986.     

Synthesis of 2-amino-3-fluoroacrylic acid containing peptides

[reaction: see text] Peptides containing (E)- and (Z)-3-fluorodehydroalanine have been prepared from serine via a fluoro-Pummerer rearrangement. The resulting electrophilic moieties may be useful affinity labels for the identification of the targets of dehydroamino acid containing natural products that act by covalent mechanisms.     

Synthesis of benzimidazole-2-carboxylic acid amides from o-phenylenediamine and oxamic acid esters

A method for the preparation of N-R amides of benzimidazole-2-carboxylic acid on the basis of the reaction between o-phenylenediamine and esters of N-R oxamic acids was developed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 684–686, May, 1982.     

Synthesis of 2-oxo and 2-thioxo-3(2H)-benzothiazoleethanimic acid anhydride with acetic acid and related products

The reaction of the appropriate 2-benzothiazolinone with 2-chloroacetamide under basic conditions afforded the 2-oxo-3(2H)-benzothiazolineacetamides 6–9. The 2-thioxo-3(2H)-benzothiazolineacetamide ( 10 ) was prepared by the reaction of 3-(carbethoxymethyl)benzothiazoline-2-thione with ammonium hydroxide. The reaction of acetamides 6–10 with the appropriate anhydride containing a catalytic amount of the sodium salt of the acid corresponding to the anhydride afforded the titled compounds 11–18 in excellent yields. The omission of the catalyst in the same reaction furnished a mixture containing 57% of the titled compound, 37% of the nitrile and 6% of an unknown. Possible mechanism and supporting nmr, ir and mass spectral data are discussed.     

Synthesis and stereochemistry of 1-acyl-2-alkyl-1,2,3,4-tetrahydroquinoline-3,4-epoxides

Summary Analogous to the recently described synthesis of Reissert epoxides the treatment of 1-acyl-2-alkyl-1,2-dihydroquinolines withm-chloroperoxybenzoic acid gave diasteromeric pure epoxides which are stable in crystalline state, but reactive in solution versus nucleophiles. Acting as useful intermediates to stereocontrolled functionalized 1,2,3,4-tetrahydroquinolines an X-ray analysis was performed to confirm the relative stereochemistry of the epoxides.

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Synthese und Stereochemie von 1-Acyl-2-alkyl-1,2,3,4-tetrahydrochinolin-3,4-epoxiden

Zusammenfassung Analog zu der kürzlich beschriebenen Synthese von Reissert-Epoxiden liefern 1-Acyl-2-alkyl-1,2-dihydrochinoline bei Behandlung mitm-Chlorperbenzoesäure diastereomerenreine Epoxide, die sich als Festsubstanzen außerordentlich stabil, in Lösung aber reaktiv gegenüber Nucleophilen erweisen. Da sie wertvolle Ausgangsverbindungen zu 1,2,3,4-substituierten Tetrahydrochinolinen mit definierter relativer Konfiguration darstellen, wurde die Stereochemie der Epoxide mittels Röntgenstrukturanalyse abgesichert.

     

Multiphase telomerisation of butadiene with acetic acid and acetic anhydride

Two different routes to acetoxyoctadiene are presented. The first one uses the well-known telomerisation of butadiene with acetic acid operating in a multiphase semi-batch mode. The second reaction involves the cleavage of acetic anhydride, hydrogen transfer via ketene formation and thus a telomerisation as well.     

Esters and amides from aziridine 2-carboxylic acid salts

Potassium salts of aziridine-2-carboxylic acid derivatives are efficiently converted into esters of amides by reactions with alkyl halides, alkyl dihalides or by acylation with trimethylacetyl chloride followed by aminolyses.     

Derivatives of 3,4-dihydro-β-carboline-3-carboxylic acid from c-terminal tryptophan-containing peptides. Synthesis and properties

C-Terminal tryptophan containing peptides have been converted into 1-peptidyl-3,4-dihydro-β-carboline-3-carboxylic acids by acid catalyzed isomerization of their azlactone derivatives. The main properties of these abnormal peptides are a strong absorption around 360 nm an intense yellow fluorescence and ability to generate reactive carbanions when dissolved in basic media. This tryptophan conversion takes place with high yield and is of general applicability.     

Synthesis of 2-substituted 7,7-dimethyl-5-oxo-5,6,7,8-tetrahydroquinoline-4-carboxylic acids

2-Substituted 7,7-dimethyl-5-oxo-5,6,7,8-tetrahydroquinoline-4-carboxylic acids were synthesized by reaction of acyl- and aroylpyruvic acids with 3-amino-5,5-dimethylcyclohex-2-en-1-one. A plausible mechanism of their formation was proposed on the basis of ab initio quantum-chemical calculations.     

Synthesis and transformation of amides of 4H-3,1-benzoxazin-4-one-2-carboxylic acid

A method for the preparation of amides of 4H-3,1-benzoxazin-4-one-2-carboxylic acid was developed, and N-R-amides of 3-R-4(3H)-quinazolone-2-carboxylic acid were synthesized from them.     

Applications and modifications of 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid (Tic) in peptides and peptidomimetics design and discovery

Tic, short for 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid, is a kind of unnatural α-amino acids. Due to its distinct geometrical conformation and biological activity, the structure of Tic, regarded as the surrogate of proline and the rigid analogue of phenylalanine or tyrosine, has been introduced into many compounds, which target diverse enzymes or receptors. The most successful example is that substituting the Tic residue for the proline residue of enalapril led to an approved drug quinapril. In this review, we will summarize the applications and modifications of Tic in peptides and peptidomimetics design and discovery, and hope to spark medicinal researchers' inspiration in the field of protein and peptide drug design and optimization.     

Reactions of the radial cattions of acetic acid and acetic anhydride in CFCl3

The ESR spectra of -irradiated, at –196 °C, solutions of acetic acid and acetic anhydride were studied depending on their concentrations in CFCl₃. The structure of thus produced radical cations is confirmed with the deuterium substituted analogues. It has been shown that the ion-molecular reaction of the radical cation CH₂COOH⁺ in the isolated dimer takes place for the dilute solutions of acetic acid in CFCl₃ resulting in the formation of CH₃COO follwed by its decomposition to CH₃+CO₂ while the radicals CH₂COOH are formed via secondary processes. The reactions of radical cations of acetic oxide have been also studied.     

Reactions of phosphoric anhydride with acyclic amides. Synthesis of amidines and imides

Acyclic secondary amides such as benzanilides 1a–g , acetanilides 2a–d , and benzamide 1h undergo self-condensation in the presence of phosphoric anhydride to produce, in one step, N-substituted aroyl benzamidines 3a–g , acyl acetamidines 4a–d , and imide 5 , respectively. Mechanistic evidence is presented for nucleophilic attack by the iminol tautomers on the O-phosphorylated amides to give amidines and on the N-phosphorylated imidates to give imides. © 1998 John Wiley & Sons, Inc. Heteroatom Chem 9:261–263, 1998     

Synthesis and properties of (6-methyl-2-oxo-4-thioxo-1,2,3,4-tetrahydro-3-pyrimidinyl)acetic acid methyl ester

On interacting of the methyl ester of (6-methyl-2,4-dioxo-1,2,3,4-tetrahydro-3-pyrimidinyl)acetic acid with the Lawesson’s reagent the corresponding 4-thioxo derivative is synthesized. Its alkylation with methyl bromoacetate has been studied as has its interaction with N-nucleophiles, amines, and hydrazines. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 590–594, April, 2007.