Synthesis and structure of some thienopyrimidine derivatives

A series of substituted thieno[2,3-d]pyrimidines was synthesized starting from ethyl-2-amino-4-isopropylthiophene-3-carboxlate. Reaction of 2-hydrazino-5-isopropyl-thieno[2,3-d]pyrimidin-4(3H)-one and its 3-methyl analogue with different reagents afforded thieno[2,3-d]triazolo[4,3-a]pyrimidines and thieno[3,2-e]triazolo[4,3-a]pyrimidines, beside open chain derivatives. Correspondence: Atef A. Hamed, Department of Chemistry, Faculty of Science, Menoufia University, Shebin El Koam, Egypt.     

Heterocyclic compounds. VI. Synthesis of poly nuclear thienopyrimidine derivatives

Quinazoline derivatives have received great interest because of their potential biological activity. This communication describes a facile method for the synthesis of substituted thiophenopyrimidones. 2-Amino-3-earbethoxy-4,5-tetramethylenethiophene on heating with substituted imidoyl-chlorides, iminoethers, iminothioethers or thioamides affords thiophenopyrimidones. By using this method a number of such compounds of varying complexity were synthesized which are otherwise not so easily accessible.     

Synthesis,reactions, and biological study of some new thienopyrimidine derivatives as antimicrobial and anti‐inflammatory agents

Pyrimidine and thienopyrimidine derivatives play a very important role in organic chemistry because of their wide applications as bioactive compounds with multiple biological activities. However, a literature survey revealed that the merger of different groups in the thieno[2,3‐d]pyrimidine heterocyclic ring enhances its antibacterial, antifungal and anti‐inflammatory activities. This encouraged us to prepare a new series of thieno[2,3‐d]pyrimidine heterocyclic compounds and to test them as antimicrobial and anti‐inflammatory agents. These compounds have shown remarkable activity toward fungi, bacteria, and inflammation. Thus, these compounds have been prepared by the chloroacylation of 5‐amino‐4‐phenyl‐2‐(p‐tolylamino)thieno[2,3‐d] pyrimidine‐6‐carboxamide ( 4 ) using chloroacetyl chloride under neat condition to afford the target compound ( 6 ), which was used as precursor for the synthesis of a number of bioactive compounds. Thus reaction of the chloromethylpyrimidine derivative ( 6 ) with triphenylphosphine in dry benzene gave the corresponding ((4‐oxo‐9‐phenyl‐7‐(p‐tolylamino)‐3,4‐dihydropyrimido[4′,5′:4,5]thieno[2,3‐d]pyrimidin‐2‐yl)methyl) triphenylphosphonium chloride ( 7 ). Compounds 8a – 8c and 9a – 9c were obtained by the reaction of 7 with some selected aromatic aldehydes and ketones in methanol and sodium methoxide under Wittig reaction condition. The structures of the all new synthesized compounds were established on the basis of their analytical and spectral data (IR, ¹H NMR, ¹³C NMR, and MS).     

Synthesis of some thiophene derivatives

The synthesis of thiopene derivatives from diacetylenic hydrocarbons has been described [1]. We have examined for the first time the reaction of diacetylenic diesters with hydrogen sulfide and with NaHS. The diacetylenic diesters react readily with hydrogen sulfide or NaHS in acetone at pH 9–10 to give 2,5-disubstituted thiopheries (see Table 1).Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 6, No. 5, pp. 713–714, May, 1970.     

Synthesis of some sym-triazole derivatives

3,5-Di(hydroxyalkyl) derivatives of 4-amino-1,2,4-triazole and the corresponding derivatives of 1,2,4-triazole obtained by diazotizing them are converted by reaction with SOCl₂ into the hydrochlorides of 4-amino-3,5-di(chloroalkyl)-1,2,4-triazoles and 3,5-di(chloroalkyl)-1, 2,4-triazoles. The dinitrate of 3,5-di(hydroxymethyl)-1,2,4-triazole has been prepared. When the cyanohydrazide of glycolic acid is heated with hydrazine hydrate, 4,5-diamino-3-hydroxymethyl-1, 2,4-triazole is formed.     

Synthesis of some phenanthridone derivatives

The alkylation of phenanthridone and some nuclear-substituted phenanthridones using sodium hydride in DMF/benzene is reported. Various 5-cyanoalkylphenanthridones were converted to further derivatives by either hydrolysis or reduction.     

Synthesis of some heptazine derivatives

Chemistry of Heterocyclic Compounds - New derivatives of heptazine were prepared from 2,5,8-trichloroheptazine by a Friedel–Crafts reaction and Pd-catalyzed amination. New...     

Synthesis of some L-idose derivatives

The synthesis of 3-0-benzyl- and 3-0-mesyl-1,2-0-isopropylidene-β′-L-iodofuranose has been effected on the basis of the intramolecular nucleophilic exchange of a mesyloxy group at C₅ in derivatives of 1,2-0-isopropylidene-α-D-glucofuranose. It has been found that in a system of vicinal primary and secondary mesyloxy groups a selective replacement of the primary mesyloxy group by an acetyl group is possible. It has been shown in benzyl and mesyl ethers of 5,6-anhydro-1,2-0 -isopropylidene-β-L-idofuranose the opening of the oxide ring under conditions of acid hydrolysis with the retention of the isopropylidene group is possible.     

Synthesis of some crotonic derivatives

Summary Eight previously undescribed dicrotonic derivatives were synthesized. Synthesis was by the reaction of hexamethylene and 2,4-tolylene diisocyanates with crotonic acid, crotonamide, N-(hydroxymethyl)crotonamide, and N -2-hydroxyethylcrotonamide.     

Synthesis of some tartaric acid derivatives

The synthesis of dimethyltartaric, diphenyltartaric and dibenzyltartaric acids as products of the reaction of V²⁺ aqueous with pyruvic, phenylglyoxylic and phenylpyruvic acids is described.     

Synthesis of some fused quinoline derivatives

Summary Preparations of the novel fused dimethoxyquinoline derivatives of furo[2,3-b]quinoline (5),s-triazolo[4,3-a]quinoline (8) and tetrazolo[1,5-a]quinoline (10) from 6,7-dimethoxy-3-car-boxyquinoline-1-oxide (1) are reported.

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Synthese kondensierter Chinolinderivate

Zusammenfassung Die Synthese der neuen kondensierten Dimethoxy-Chinolinderivate Furo[2,3-b]chinolin (5),s-Triazolo[4,3-a]chinolin (8) und Tetrazolo[1,5-a]chinolin (10) aus 6,7-Dimethoxy-3-carboxychinolin-1-oxid (1) wird beschrieben.

     

Condensed thienopyrimidines. II. Synthesis and gastric antisecretory activity of thiazole and polymethylene condensed thienopyrimidine derivatives

Thiazolo[3,2-a]thieno[3,2-d]-, [3,4-d]- and [2,3-d]pyrimidin-5-one derivatives (6, 11 and 16), and polymethylene condensed thieno[3,2-d]-, [3,4-d]- and [2,3-d]pyrimidin-5-one derivatives (19-21), in which the oxygen atom of the oxazolidine moiety in 3 was replaced by a sulfur atom or methylene groups, were synthesized and evaluated for gastric antisecretory activity in pylorus-ligated rats. The structure-activity relationships of these compounds are discussed.     

Synthesis of new 1,2,4-oxadiazolidin-5-ylthiophenes and thienopyrimidine derivatives by aza-Wittig reaction using a thienyl carbodiimide

Azidation of aminothiophene derivative 1 afforded the corresponding azido derivative 2.The latter reacted with triphenylphosphine to afford iminophosphorane derivatives 3.Reacting 3 with phenylisocyanate gave the highly reactive carbodiimide intermediate 4,which was reacted with different nitrones to afford new l,2,4-oxadiazolidin-5-ylidene-aminothiophenes 5a-c. Treatment of 4 with absolute EtOH at room temperature gave methyleneamino-5-(methylthio)thiophene 7,(methylthio)-3-(3- phenylureidothiophene)-2-carboxylate 8 or thienopyrimidine 9 and 10 at refluxing temperature.Finally reaction of carbodiimide intermediate 4 with different secondary amines gave the new thienopyrimidines 11a-c.     

Synthesis of some trifluoroethyl-substituted derivatives of aniline

A new procedure is presented for the preparation of N-trifluoroethylanilines by reaction of the appropriate aniline with ethyl trifluoroacetate or trifluoroacetic anhydride, followed by reduction with diborane in tetrahydrofuran. Yields are high unless the aniline carriers a carboyxl, carbonyl, olefin, or o-nitro substituent. several new N-substituted trifluoroacetamides and trifluoroethylanilines are reported.     

Synthesis of some oxadiazole derivatives of d-mannose

The syntheses of 2-methyl-5-[1′,2′,3′,4′,5′-penta-O-benzoyl-D-manno-pentitol-1′-yl]-1,3,4-oxadiazole and 5-methyl-3-[1′,2′,3′,4′,5′-penta-O-benzoyl-D-manno-pentitol-1-′yl]-1,2,4-oxadiazole, as well as their intermediate products, are described. Their ¹H and ¹³C nmr and ms spectra are presented and their preferential conformation in solution are proposed.