International Journal of Organic Chemistry, 2012, 2, 135-142 http://dx.doi.org/10.4236/ijoc.2012.22021 Published Online June 2012 (http://www.SciRP.org/journal/ijoc) An Efficient and Convenient Synthesis of Certain 2-Thioxothiazole,2-oxo-1,2-dihydropridine, 2-Oxo-2H-pyran,2,4-diaminothiophene and Pyrazolo[5,1-c][1,2,4]triazine Derivatives Containing Antipyrine Moiety Seif-Eldin Nasr Ayyad 1,2 , Fathy Muhammad Abdelaziz El-Taweel 2* , Abdel-Ghani Ali Elagamey 2 , Tahani Mahmoud El-Mashad 2 1 Department of Chemistry, Faculty of Science, King Abdulaziz University, Jeddah, KSA 2 Department of Chemistry, Faculty of Science, New Damietta Branch, Mansoura University, New Damietta, Egypt Email: * fathyeltaweel@yahoo.com Received February 18, 2012; revised March 9, 2012; accepted March 23, 2012 ABSTRACT 2-Thioxothiazole derivatives 5a-c were prepared by reacting a mixture of 1a-c, CS 2 /KOH and 4-(2-chloroacetyl)-1, 5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one (3). Reacting 2-cyano-N-(4-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H- pyrazol-4-yl)-2-thioxothiazol-3(2H)-yl)acetamide (5c) with mercaptoacetic acid, arylidenemalononitriles 8 and (E)- 3-(dimethylamino)-1-(furan-2-yl)prop-2-en-1-one (12) give 4-oxo-4,5-dihydrothiazole 6, 2-oxo-1,2-dihydropyridine 10 and 2-oxo-2H-pyran 15 respectively. Heating a mixture of 5c, malononitrile and elemental sulfur yield 2,4-diaminothio- phene 19. Coupling of 5c with the diazotized aminopyrazole 20 and aryldiazonium salts 23 give pyrazolo[5,1-c][1,2,4] triazines 22 and arylhydrazones 25 respectively. Keywords: Thioxothiazoles; Pyridine; Thiophene; Pyrazolotriazines 1. Introduction Diverse pharmacological properties have been associated with thiazole derivatives [1-3]. These pharmacological activities have been attracted special attention to prepare a new class of thiazole derivatives carrying antipyrinyl moiety because of their applications in the field of phar- maceuticals [4-6] and antibacterials [7-9]. The present work reports the synthesis of certain thiazole derivatives containing antipyrine moiety using readily available start- ing materials. 2. Experimental All melting points are uncorrected and have been meas- ured on a Griffin & George MBF010T (London) appa- ratus. Recorded yields correspond to the pure products. IR (KBr) spectra were recorded on a Perkin Elmer SP- 880 spectrometer and from samples of sufficient solubil- ity. 1 H-NMR spectra were measured on a Varian 270 MHz spectrometer on DMSO-d 6 as solvent and TMS as an inter- nal standard. Chemical shifts are reported in δ units (ppm). Microanalyses were performed on a LECO CHN-932 elemental analyzer and carried out in the Microanalytical Data Units at Cairo and Mansoura Universities. General procedure for preparation of 4,4’-(2-thioxo- thiazole-3,4-(2H)-diyl)bis(1,5-dimethyl-2-phenyl-1H- pyrazol-3(2H)-one)(5a),2-(4-chlorophenoxy)-N-(-(1,5-di- methyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)-2- thioxothiazol-3(2H)-yl)acetamide(5b) and 2-cyano-N-(4- (1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4- yl)-2-thioxothiazol-3(2H)-yl)acetamide(5c) A solution of 4-amino-1,5-dimethyl-2-phenyl-1H-pyra- zol-3(2H)-one (1a) or 2-(chlorophenoxy)acetohydrazide (1b) or 2-cyanoacetohydrazide (1c) (0.01 mol) in dimethyl- formamide (30 mL) containing potassium hydroxide (0.01 mol) and (0.01 mol) of carbon disulfide was stirred at room temperature for 6 h. To this solution (0.01 mol) of 4-(2-chloroacetyl)-1,5-dimethyl-2-phenyl-1H-pyrazol-3 (2H)-one (2) was added, then the solution was stirred again overnight, poured on ice and neutralized with dilute hydrochloric acid. The precipitates formed were collected by filtration and crystallized from ethanol to give 5a-c respectively. 4,4’-(2-Thioxothiazole-3,4-(2H)-diyl)bis(1,5-dimethyl * Corresponding author. Copyright © 2012 SciRes. IJOC