Synthesis and Molluscicidal Activity of Some 1,3,4‐Triaryl‐5‐chloropyrazole, Pyrano[2,3‐c]pyrazole, Pyrazolylphthalazine and Pyrano[2,3‐d]thiazole Derivatives

Abstract

2-(5-Chloro-1,3-diphenyl-1H-pyrazol-4-ylmethylene)-malononitrile 1a reacts with the arylidenes of malononitrile 2a-d to afford the triaryl-5-chloropyrazoles 3a-d, respectively. 1a reacts with the active methylene pyrazolinones 5a, b and 12a, b to afford different products 8, 9, 10, 11, and 14a, b--depending on the substitution in the pyrazole ring. Compound 1a reacts also with the pyridazinone derivative 15 to afford the phthalazinone 16, and with the thiazolinones 17a-c to afford the pyrano[2,3-d]thiazoles 20a-c, respectively. It reacts also with the malononitrile dimer 21a and with ethyl cyanoacetate dimer 21b to yield the pyrazolyl pyridines 22a, b, respectively. The synthesized compounds showed a moderate molluscicidal activity towards Biomphalaria alexandrina snails.

Chitosan as heterogeneous catalyst in Michael additions: The reaction of cinnamonitriles with active methyls, active methylenes and phenols

“…41 Thus, we have measured 1 H NMR, 13 C NMR, HMBC and HMQC. It was noted in HMBC that the carbonyl carbon atom at 165 ppm is coupled to the arylmethylene proton at 7.85 ppm.…”

Green methodologies in organic synthesis: recent developments in our laboratories

“…The structures of the products of these reactions were established using HMBC and heteronuclear multi-quantum correlation (HMQC) techniques. The findings contrast to the reported formation of pyronothiazoles 10 in similar reactions [13]. Green Chemistry Letters and Reviews 191 Enaminones 11 are produced via reactions of methyl ketones with dimethylformamide dimethylacetal (DMFDMA) [14] in refluxing toluene [15], but the yields of these processes are rather poor.…”

“…Thus, when equimolar Green Chemistry Letters and Reviews 193 amounts of 37 and (E)-2-nitrophenylarenes 38 in dioxane are irradiated using a microwave lab station at 100 8C in the presence of piperidine (2 drops), the corresponding polysubstituted diaminobenzonitriles 39 are generated rather than the corresponding 2-cyanomethylpyridine derivatives 40. The structures of 39 were established using 1 H NMR and 13 C NMR spectroscopic analysis (Scheme 10 and Table 7) [27].…”

“…It occurred to us that it might be valuable to probe in detail the actual structures of some of these products, which have been questioned [67,68]. Chitosan is hydrophilic basic catalyst and, as such, it has been used successfully as a catalyst for Michael addition reactions (Scheme 20) [69].…”

The anticancer potential of various substituted pyridazines and related compounds

“…We employed the protected N-phenylimide as the electrophile. The pyridazinone (1a) was converted into the chloro compound (2). Preliminary evaluation of the cytotoxic activity of 3-azaolivacine (3) towards four human tumor cell lines, using the XTT assay, showed significant effects only at a relatively high concentration of 3.16m g/ml, whereas at lower concentrations no dose-dependent activity was observed.…”