synthesis of some novel pyrazolo[1,5-a]pyrimidine derivatives and their application as disperse dyes合成一些新奇pyrazolo(1、5)嘧啶衍生物及其应用分散染料.pdf

Molecules 2011, 16, 5182-5193; doi:10.3390/molecule OPEN ACCESS molecules ISSN 1420-3049 /journal/molecules Article Synthesis of Some Novel Pyrazolo[1,5-a]pyrimidine Derivatives and Their Application as Disperse Dyes Alya M. Al-Etaibi 1,*, Nouria A. Al-Awadi 2, Morsy A. El-Apasery 2 and Maher R. Ibrahim 2 1 Natural Science Department, College of Health Science, Public Authority for Applied Education and Training, Kuwait 2 Chemistry Department, Faculty of Science, Kuwait University, P.O. Box 5969, Safat 13060, Kuwait * Author to whom correspondence should be addressed; E-Mail: alya.aletaibi@. Received: 1 June 2011; in revised form: 9 June 2011 / Accepted: 15 June 2011 / Published: 22 June 2011 Abstract: A series of novel monoazo-disperse dyes containing pyrazolo[1,5-a]pyrimidine structures were synthesized starting with the coupling reaction between ethyl cyanoacetate and 4-hydroxybenzenediazonium chloride, followed by treatment of the resulting hydrazone product with hydrazine hydrate. The pyrazolohydrazone 6 is then treated with either 2,4-pentandione and enaminonitrile or aryl-substituted enaminoketones to give the target pyrazolo[1,5-a]pyrimidine dyes 7 and 15a-d. Structural assignments to the dyes were made using NMR spectroscopic methods. A new high temperature method, using microwave heating, was employed to apply these dyes to polyester fibers. Most of the dyed fabrics tested displayed moderate light fastness and excellent washing fastness properties.