ChemInform Abstract: Site Selectivity in Reaction of Hydrazonoyl Halides with 2‐(Aroylmethyl)‐6‐methylpyrimidin‐4(3H)‐ones.

Abstract

Pyrimidine derivatives R 0510Site Selectivity in Reaction of Hydrazonoyl Halides with 2-(Aroylmethyl)-6-methylpyrimidin-4(3H)-ones. -Depending on the substituents, the reaction of hydrazonoyl halides (II) or (IV) with pyrimidin-4-one derivatives (I) gives open-chain compounds of type (V) or the corresponding cyclized products (III). -(SHAWALI*, A. S.; FARGHALY, T. A.; J. Chem. Res. 2008, 12, 688-692; Dep. Chem., Fac. Sci., Cairo Univ., Giza 12613, Egypt; Eng.) -M. Bohle 21-160

Regioselective synthesis of some functionalized 3,4’-bis-(pyrazolyl)ketones and chemoselectivity in their reaction with hydrazine hydrate

“…This is because the 1 H NMR spectra of the products 4(5) isolated showed in each case a singlet signal in the region δ 8.60-9.22, which corresponds to H-5 of the pyrazole ring residue in the products. This assignment is consistent with literature reports which indicate that in pyrazole derivatives, the signal of H-5 usually appears at δ 8.66-8.69 whereas that of H-4 appears at δ 5.81-5.89 [25]. The formation of compounds 4(5) rather than compound 6 indicates that the studied reaction of compound 1 with compounds 2(3) is regiospecific.…”

Synthesis, Reactions and Antitumour Screening of new Enaminones

“…3 Condensation of each of the pyrazoles 5a-e with N,N-dimethylformamidedimethylacetal (DMF-DMA) yielded the respective enaminones 6a-e in 75-85% yield (Scheme 1). The structures of the enaminones 6a-e were confirmed by their spectra (MS, IR and 1 H NMR (see Experimental). For example, their IR spectra revealed two carbonyl bands in the regions ν 1721-1668 and 1649-1642 cm −1 .…”

Hydrazonoyl Halides as Precursors for Synthesis of Novel Bioactive Thiazole and Formazan Derivatives

“…In addition to these findings, formazans and heterocyclic hydrazones are known for their diverse biological activities. [10][11][12] As part of our ongoing interests in the reactions of hydrazonoyl halides with several heterocyclic compounds to synthesise bioactive compounds, [13][14][15] we investigated the reaction of hydrazonoyl halides with benzocyclohepten-5-one thiosemicarbazones and benzocyclohepten-5-one hydrazone to give new derivatives of thiazole and substituted formazan which were expected to be biologically active. We also elucidated the actual tautomeric structures of such thiazole derivatives as they can have one or more of eight possible tautomeric forms (Scheme 2 and Fig.…”