سنتز و شناسايي مايع يوني اسيدي 3- كربوكسي پيريدينيوم هيدروژن سولفات﴿ HCPY] HSO4 ﴾ و كاربرد آن در سنتز تركيبات بنزوزانين، 3، 4- دي هيدروپيريميدين

چكيده انگليسي :

The synthesis and characterization of 3 carboxypyridiniumhydrogensulfate Hcpy HSO4 acidic ionic liquid and application of it for synthesis of benzoxanthenes 3 4 dihydropyrimidin 2 1H ons aryl azides and aryl iodide Mohadeseh Seddighi m seddighi@ec iut ac ir Date of Submission 2009 11 15 Department of chemistry Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor Abdol R Hajipour haji@cc iut ac irAbstractOver the last years ionic liquids have been used as solvent or catalyst in organic synthesis due to theirremarkable properties as non flammable negligible vapor pressure high thermal chemical andelectrochemical stability easy recyclability and high solvating ability Br nsted acidic ionic liquids also havebeen found abrupt improvement as catalyst or dual rule of catalyst and solvent in many reactions Thepyridinium based ionic liquids have less attention versus other cations So the synthesis characterization andapplication of 3 carboxypyridinium hydrogensulfate Hcpy HSO4 as a green efficient and inexpensivepyridinium based Br nsted acidic ionic liquid has been reported The synthesis of benzoxanthenes haveattracted considerable interest due to their biological and pharmaceutical properties 3 Carboxypyridiniumhydrogensulfate has been employed as efficient catalyst for one pot condensation of naphthol andaromatic aldehydes at 120 oC for synthesis of the corresponding 14H dibenzo a j xanthene The reactioncarried out under solvent free conditions and the procedure gave the products in good to excellent yieldsunder green conditions Using less catalyst straightforward isolation of products only with water and alsoreusability of catalyst were other advantages of this method 3 4 Dihydropyrimidin 2 1H ones are one classof multicomponent reactions that they exhibit a wide range of biological and pharmacological properties One of the most important methods for synthesis of this class of compound is the one pot condensation of analdehyde ketoester and urea under acidic conditions first reported by Biginelli 3 Carboxypyridiniumhydrogensulfate has been used as acidic catalyst for synthesis of these compounds at 120 oC under solvent free conditions The procedure gave the products in very short time with excellent yields Aryl azides areversatile intermediates that due to azide group have been found wide application in organic synthesis sincethey can be used for preparation of a variety of heterocycles The general procedure for preparation of arylazides is using aromatic amines and nitrous acid in two steps diazotization of the amine and subsequenttreatment with sodium azide The reaction must carry out at low temperature 0 oC due to instability ofdiazonium salt in aques media In continuation of our effort to study of application of Hcpy HSO4 acidicionic liquid it was employed as acid source for synthesis of aryl azides from corresponding amines undergrinding condition The reaction carried out under green conditions at room temperature with short reactiontimes and the products obtained with excellent yields The products were isolated and purified only withwater without using any organic solvent Furthermore not only the producing diazonium salts are stable atproducing time but also can be restored for long time at room temperature In continuation this procedurewas used for the preparation of aryldiazonium salts and employing these versatile and stable intermediates inSandmeyer reaction iodoaromatic compounds are the most useful synthetic building blocks in organicsynthesis mainly for C C and C N bond formation in metal catalyzed cross coupling reaction Also they canbe employed for the synthesis of pharmaceutical and bioactive compounds Short reaction times high toexcellent yield stability of diazonium salt under mild conditions are many of advantages of this method Keywords Acidic ionic liquid 3 Carboxypyridinium hydrogensulfate 3 4 Dihydropyrimidin 2 1H one Biginellireaction Arylazide Aryl iodide Diazoniu

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