Nitriles in Heterocyclic Synthesis. A Novel Synthesis of 4-Phenacylpyrazole and Pyrrolo[2,3-c]pyrazole Derivatives

Simple Efficient Routes for the Preparation of Pyrazoleamines and Pyrazolopyrimidines: Regioselectivity of Pyrazoleamines Reactions with Bidentate Reagents

“…Dihydrofuran derivative (12) was observed to react readily with hydrazine hydrate to yield the 3,5-diaminopyrazole derivative 2h (Scheme 3). In contrast, tetrahydrofuran derivative (13) reacts with hydrazine hydrate to yield pyrazolone 14 and with benzenediazonium chloride to form 5-phenyl-3-(2-phenylhydrazono)-dihydrofuran-2(3H)-one (15). The structures of 2h, 14, and 15 were assigned by using X-ray crystallography (see supporting information: Figures 2-4, Tables 3-8).…”

“…[6,[8][9][10] In related studies, mono-substituted malononitriles 1b-f were shown to be useful for the efficient synthesis of diaminopyrazoles 2b-f. [11][12][13][14] However, the formation of 2g via reaction of phenacyl malononitrile (1g) with hydrazine hydrate could not be repeated in our hands. [15][16][17] Treatment of 1g with hydrazine hydrate in ethanolic solution as described by Abdelrazek et al [15][16][17] or in absence of solvent in dry condition as suggested recently [18] has only result in the formation of 6 in 97% yield. What is more, the use of dry conditions was claimed even though hydrazine hydrate already contains one molecule of water.…”

Heterosynthesis Using Nitriles: Novel Pyrrolo[2,3-<i>b</i>]pyridines

“…We have reported the synthesis of a variety of pyrrole, N-substituted pyrrole and fused-pyrrole derivatives of biological interest [9][10][11][12][13][14][15][16]. Recently some pyrrolo [2,3-b] pyridine derivatives were shown to be effective as inhibitors of tumor necrosis factor alpha [17].…”

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

“…In the last two decades, we have been involved in a program aiming at the synthesis of heterocyclic compounds of anticipated biological activity that may find applications as biodegradable agrochemicals [1][2][3][4]. Schistosomiasis (bilharziasis) is one of the major national health problems in Egypt and great efforts are made to combat this disease.…”

“…We have found it mandatory to participate in these efforts and directed a part of our research towards the synthesis of heterocyclic compounds that can be used as molluscicides [5,6]. Pyrazoles and their fused derivatives are known to exhibit diverse biological activities and important applications in pharmaceutical industries [1, 2,7,8]. In continuation of our search for some effective synthetic molluscicides, chloropyrazole derivatives seemed promising for molluscicidal activity evaluation.…”