Another condensed pyrazole could be obtained when 1 was refluxed with 1-amino-4,6-diphenyl-2-methylthiopyridinium iodide 8, where cyclization took place giving a product which was identified as 2 -amino-3-hydrazinocarbox-5,7diphenylpyrazoio[2, 3-a ]pyridine 9 (Scheme 3). Moreover, it was found that the reaction of compound 10 with cyanoacetohydrazide 1, yield a product which was interpreted as the α-iminopyran derivative 11 (Scheme 4). Similarly, it has been reported that, the reaction of Nsubstituted cyanoacetohydrazide 12 with salicylaldehyde gave α-coumarin derivatives 13 as shown in Scheme 5. Goher et al reported the isolation of both the α-coumarin derivative and its imino analogue 15 from the reaction of 1 with the condensed salicylaldehyde 14 in ethyl alcohol containing catalytic amount of piperidine (Scheme 6) . Additionally, novel structures containing thiazolo pyridine-fused spirooxindole 22 were synthesized 9 by a four-component domino reaction of cysteamine hydrochloride 19, nitroketene dithioacetals 20, isatin or its derivatives 21 and cyanoacetohydrazide 1 (active methylene compound) in ethanol under reflux conditions (Scheme 8). As for isatin derivatives (5-bromoisatin and 5-chloroisatin), due to the relatively less activity of these derivatives than isatin, the reaction was conducted via using nanoSiO 2 (20 mol%) as an effective heterogeneous Lewis acid promoter. There are several reactions in which cyanoacetohydrazide undergoes first selfcyclization involving the cyano and amino -groups to give 3-amino-5-pyrazolone 23, then the latter compound reacts with the available reagent present in the reaction mixture. Due to the presence of more than one reactive center in compound 23, the center (or centers) involved in the reaction course depends on the other reactant and the experimental conditions used. Its worthy to mention that compound 23 could be obtained by treatment of 1 with 40 % NaOH followed by neutralization with 50% AcOH 1 as shown in Scheme 9.