Parham cyclisation – intermolecular α-amidoalkylation sequence constitute a route to trans thiazolo[4,3-a]isoquinolinones. These thiazolidindiones, that incorporate allyl groups at C-1 and C-10b, are efficient precursors of thiaerythrinanes by ring-closing methathesis reactions.

The reaction of MND with aryldiazonium chlorides followed by cyclization afforded the pyridazinimine derivatives. Reaction of the latter with another mole of malononitrile produce only pyrido[3,2-c]pyridazine derivatives. Reaction of 4-aminopyridazinone-3- carboxylix acid esters with malononitrile gave only pyridazine-3-carboxylic acid.

This work is the continuation of a collaboration with a Portuguese group involved since several years in the development of organic compounds having some peculiar physical behavior. For such an application, these compounds should posses the following structure: heterocyclic conjugated p system bearing an electron-acceptor and an electrondonor group.

The addition of the hypervalent iodine reagent PIFA [phenyliodine(III) bis(trifluoroacetate)] to a series of styrene type compounds results in the bis(trifluoroacetoxylation) of the double bond as two possible 1,2- and 1,1-regioisomers. We found that 1,1-regioisomers resulted to be unstable during chromatographic purification yielding the related arylacetaldehydes. In this communication we show our efforts to explore the regioselectivity of this reaction, and to rationalize the results with respect to the electronic nature of the corresponding aryl ring through alternative mechanistic pathways.

Unsymmetrically substituted A 3 B-phthalocyanine derivatives bearing annulated 6-membered N-heterocycles, pyridine and pyrazine rings, have been synthesized by ring expansion reaction of subphthalocyanines. The geometrically constrained subphthalocyanines (A 3 ) were reacted with 1,2-phthalonitrile derivatives (B), in presence of 8-diazabicyclo[5.4.0]undec-7-ene (DBU), to form the A 3 B-phthalocyanine. The reactions were carried out in DMSO/1- chloronaphthalene at 130-140 °C for 15 h. This approach produces selectively A 3 B-phthalocyanines with high yields (75-90%) and it requires simple purification procedure since there are not byproducts. The spectroscopic properties of the A 3 B-phthalocyanines were compared with its homologous non-substituted Zn(II)phthalocyanine. In these compounds, annulated 6-membered N- heterocycles are precursors of cationic groups by methylation and therefore they represent interesting agents with potential applications in photodynamic inactivation of microorganisms.

Three multidentate Schiff-base ligands were obtained by condensation of different diamines (1,3-diaminopropane, 1,3-diamino-2,2-dimethylpropane, 1,4-diaminobutane) and 3-methoxy-2-hydroxybenzaldehyde to yield H 2 L n (H 2 L 1 , H 2 L 2 and H 2 L 3 , respectively). The ligands have been characterised by elemental analysis, IR, and 1 H and 13 C NMR spectroscopies, mass spectrometry (ES) and X-ray diffraction.

During study of pyromellitic anhydride condensation with 1,2-phenylenediamine to bisbenzimidazole pigment new condensation product, di-2,3-(2-benzimidazolyl)-benz[4,5]imidazo[2,1-a]isoindol-11-one was obtained.

The comparative study for reduction of anthraquinone and alizarin with zinc dust and zinc amalgam was conducted. Both reactions gives 9,10-dihydroanthracene, 1,2,3,4-tetrahydroanthracene, and 1,2,3,4,4a,9,9a,10-octahydroanthracene mixtures as reaction products. No any hexahydroanthracene isomers were detected by GC-MS.

The unexpected tendency of amines and functionalized hydrazines to reduce the ethyl 3-phenylquinoxaline-2-carboxylate 1,4-di-N-oxide (1) to a quinoxaline (1c) and mono-oxide quinoxalines (1a and 1b) is described. The experimental conditions were standardized in the use of 2 equivalents of amine in ethanol under reflux for 2 hours, with the aim of studying the distinct reductive profile of the amines and the chemoselectivity of the process. With the exception of hydrazine hydrate, which reduced compound 1 to a 3- phenyl-2-quinoxalinecarbohydrazide derivative, the amines only acted as reducing agents.

Some compounds of 1-(2’,3’,4’,6’-tetra-O-acetyl-ß-D-glucopyranosyl)-3-(4”,6”- diarylpyrimidine-2”-yl)thioureas have been synthesized from corresponding isothiocyanates and 2-amino-4,6-diarylpyrimidines using two different synthetic methods. The hydrolysis of these acetated thioureas lead to form the corresponding deacetyled thioureas. Their spectroscopic properties have been studied.