Month 2016 Synthesis of Thiazolinone, Aminopyrazole, Pyrazolopyrimidine, and Pyrazolotriazine Derivatives Starting from 1-Naphthyl-2-Cyanoacetamide Ahmed A. Fadda, Ramy Rabie, * and Hassan A. Etman Chemistry Department, Faculty of Science, Mansoura University, Mansoura, Egypt *E-mail: rabieshafek@yahoo.com Additional Supporting Information may be found in the online version of this article. Received November 19, 2015 DOI 10.1002/jhet.2669 Published online 00 Month 2016 in Wiley Online Library (wileyonlinelibrary.com). Efficient and suitable methods for the synthesis of novel class of simple and fused heterocyclic compounds were prepared starting with 1-naphthyl-2-cyanoacetamide and commercially available reagents. The cyclocondensation of 1-naphthyl-2-cyanoacetamide with sulfanylacetic acid furnished phenylthiazolinone derivative. Stirring of the starting compound with PhNCS afforded thiocarbamoyl derivative which underwent heterocyclization with chloroacetyl chloride to give thiazolinone derivative. 5-Aminopyrazole derivative was prepared by following mild procedures via refluxing the last thiocarbamoyl with hydrazine hydrate. Different synthetic approaches were discussed to obtain the novel fused pyrazolo[1,5-a]pyrimidine, 4H-pyrazolo[3,4-d]pyrimidin-4-one moieties in- volving the reaction of the prepared 5-aminopyrazole with a) 1, 3-dielectrophilic centers (acetylacetone, acetoacetanilide), b) arylidines of malononitrile, and c) isothiocyanate derivatives. The action of iced sodium nitrite solution in acidic medium on the last 5-aminopyrazole gave pyrazolo[3,4-d][1,2,3]triazine. All novel structure were elucidated by different spectroscopic data (IR, MS, 1 H, and 13 C NMR) and elemental analysis. J. Heterocyclic Chem., 00, 00 (2016). INTRODUCTION Cyanoacetamides are versatile reagents, and their chemis- try has recently received a considerable attention as precur- sors to construct several novel heterocyclic moieties [1–6]. Thiazole ring system is considered one of the most important products derived from cyanoacetamides derivatives. It is a common moiety found in numerous biologically active mol- ecules. Many derivatives of this system showed antibacterial [7], antimicrobial [8], antitumor [9], and anti-inflammatory activities [10]. Another important product was pyrazole rings; it is known to possess a significant effect against breast cancer cell line (MCF7) [11]. Also it has been employed in the preparation of different fused heteroatom rings which have useful biological activities [12–15]. One of the most important fused derivatives are pyrazolopyrimidines, which has received a great attention because of their pharmacolog- ical activity such as allopurinol (zyloric R) [16], and silden- afil that is utilized for treatment of male erectile dysfunction [17]. On the other hand, zaleplon is a well-accepted drug for treatment of insomnia [18]. (cf. Fig. 1). Complementing to our aim in the synthesis of heterocycles utilizing cyanoacetamides as starting materials [19–21], we hope to procedure new moieties of thiazole and pyrazole rings fused with different heterocyclic moieties that may possess less toxic properties and great antimicrobial effect. © 2016 Wiley Periodicals, Inc.