%0 Journal Article
%T An Efficient, Clean, and Catalyst-Free Synthesis of Fused Pyrimidines Using Sonochemistry
%A M. Mamaghani
%A K. Tabatabaeian
%A R. Araghi
%A A. Fallah
%A R. Hossein Nia
%J Organic Chemistry International
%D 2014
%I Hindawi Publishing Corporation
%R 10.1155/2014/406869
%X In this report, synthesis of indenopyrido[2,3-d]pyrimidine and pyrimido[4,5-b]quinoline derivatives was investigated via one-pot three-component reaction between 6-amino-2-(alkylthio)-pyrimidin-4(3H)one, 1,3-indanedione, or 1,3-cyclohexadione and arylaldehyde under ultrasonic irradiation in ethylene glycol as solvent at 65∼C. In these reactions fused pyrimidine derivatives were synthesized with high to excellent yields (82每97%) and short reaction times (10每33ˋmin). 1. Introduction Pyrimidine structural moiety constitutes a major class of heterocyclic compounds which have various pharmaceutical applications. For example, they are found to possess antineoplastic [1每3], antiviral [4每6], antibiotic [7], and anti-inflammatory properties [8]. Pyrimidines also exhibit a range of pharmacological activities such as antibacterial [9每11], antifungal [12, 13], anticancer [14, 15], and cardioprotective effects [16]. Bicyclic and tricyclic fused pyrimidine derivatives have received much attention in connection with biologically significant systems such as pyrido[2,3-d]pyrimidines. Pyrido[2,3-d]pyrimidine structural motif is present in pirenperone (tranquilizer) [17] and ramastine (antiallergic) [18], as well as in some antiulcerative and antiasthmatic agents [19]. In addition, quinolines have pharmacological properties which include wide applications in medicinal chemistry; for example, this scaffold structure is present in anti-inflammatory agents, antimalarial drugs, and antihypertensive, antiasthmatic, antibacterial, and tyrosine kinase inhibiting agents [20每25]. Moreover the importance of uracil and its annulated derivatives is well recognized by synthetic [26, 27] as well as biological [28, 29] chemists. The 6-amino-uracil derivatives represent very important classes of functionalized uracils; also 6-amino-uracils find wide applications as starting materials for the synthesis of a number of fused uracils of biological significance, for example, pyrano-, pyrido-, pyrazolo-, pyrimido-, and pyridazinopyrimidines [30, 31]. On the other hand, ultrasonic reactions have been increasingly used as clean, green, and environmentally benign routes for the preparation of organic compounds of synthetic and biological values [32每37]. A large number of organic reactions can be carried out in higher yield, shorter reaction time, and under milder conditions, by using ultrasonic irradiation [38每41]. These observations led us to attempt the synthesis of some new fused pyrimidine derivatives using 6-amino-alkyltiouracil as starting material under sonochemical conditions. The present
%U http://www.hindawi.com/journals/oci/2014/406869/