Reactions of cyclic oxalyl compounds, synthesis of functionalized hydrazono-2H-imidazol-4,5(1H, 3H)dione: Experimental data and AMI calculations

The reaction of the 4-benzoyl-5-phenylfuran-2,3-dione (1) with guanylhydrones, (2a-d) gives hydrazono-2H-imidazol-4.5-(1H,3H)-dione derivatives (4a-d) (yield ca. 30-40%). The structure of these compounds were determined by spectroscopic methods. Quantum chemical calculations were carried out for 2a-d and 4a-d by AM I method

Synthesis of novel proponohydrazides and their hydrolysis reactions

4-(4-Methoxybenzoyl)-5-(4-methoxyphenyl)-2,3-furandione 1 reacted with N-aryl substituted phenyl-hydrazones 3a-h via the p,p'-dimethoxydibenzoylketene intermediate 2 giving the proponohydrazide derivatives 5a-h. In addition, compounds 5a-h were converted into corresponding pyrazolone derivatives 7i,j by the reactions of hydrolysis in acidic solution. The structures of these new synthesized compounds were determined by C-13 NMR, H-1 NMR and IR spectroscopic data and elemental analysis

Synthesis of some pyrazole-3-carboxylic acid-hydrazide and pyrazolopyridazine compounds

Furan-2,3-diones la-c react with various hydrazines 2a-c under different conditions to yield the pyrazole-3-carboxylic acid-hydrazide 3a-d. Cyclocondensation reactions of la or 7 with phenylhydrazine lead to derivatives of pyrazolo[3,4-d]pyridazinones 6 and 8, respectively. The structures of all products were confirmed by elemental analysis, IR, H-1- and C-13-NMR spectroscopic measurements

A new method for the preparation of pyridazine systems: Experimental data and semiempirical PM3 calculations

The reactions of 4-benzo3,1-5-phenyl-2,3-furandione (1a) and 4-(4-methoxybenzoyl)-5-(4-methoxyphenyl)2.3-furandione (1b) with acyl hydrazines (2) (namely hydrazides) are reported. From these reactions, novel pyridazinone systems (3a-g) are obtained as well as the cyclization product of 3g at high temperature (4). The electronic properties and conformational parameters for these molecules, such as bond lengths, bond angles, torsion angles and atom charges, are calculated with a semiempirical PM3 method. In order to determine the mechanism of the reaction between the model furandion (R1) and formic hydrazide (R2), the electronic properties, conformational parameters and imaginary frequencies of the reactants, transition states and intermediates are calculated at the same level of theory as well

On the synthesis of some N-Alkyl Pyrimidine derivatives and determination of their structures

In this study, reactions similar to the Michael-type nucleophilic cycloaddition of the 4-panisoyl-5-p-anisyl-2,3-furandione (1) with monosubstituted ureas and thioureas 2a-g gave N-alkyl pyrimidine derivatives 3a-g, with loss of carbon dioxide and water. These new heterocyclic compounds 3a-g were obtained in moderate to excellent yields 40-96%. The compound 1 was easily prepared by the reaction of dianisoylmethane with oxalyl dichloride. First the compounds 3 were synthesized, the results obtained were then interpreted. The structures of the compounds 3a-g were determined by the H-1 NMR, IR spectroscopy and elemental analyses