On the other hand, when the above reaction was carried out at room temperature, the compound 25 was obtained which could be converted into the corresponding cyclized analogue on boiling its solution in ethanol and triethylamine (Scheme 11). In some other cases, the addition to the activated double bond can take place by the amido NH group of the pyrazolone ring, for example the reaction of 1 with phenyl isothiocyanate 27 in refluxing dioxane and the separated product was defined as the 1-phenylthiocarbamoyl-3-amino-5-pyrazolone 28 as shown in Scheme 12. Also, it has been reported by Ghoneim et al. that when 1 reacted with at αbenzylidene-2-cyanomethylbenzothiazole 29, a product interpreted as 1:1 Michael adduct 30 was obtained (Scheme 13). Some reactions involved the active centers, amino and active methylene groups of the pyrazolone ring and as aresult a number of Pyrazolopyridines were formed. Thus, when El-Wassimy et al. reacted 1 with the α,β-Unsaturated ketones 31 or 32, they separated products which have been interpreted as the 4,6disubstituted -2H -pyrazolo [ 4,3b] pyridin-3-ones 33 or 34 , respectively . These reactions are believed to proceed via a Michael addition by the active methylene on the activated double bond of the chalcone giving the corresponding 1:1 Michael adducts which then undergo self -cyclization with elimination of water as shown in Scheme 14. Also, it has been reported that, the reaction of 2'-acetyl-2-cyanoacetohydrazide 35 with α-carboalkoxy cinnamonitriles 36 in methanol -piperidine gave products interpreted as the pyrazolo [3,4-