Methods for the bromination of porphyrins and their derivatives at the meso and β-positions are examined. The dependence of the course of the reactions on the conditions and on the structure of the initial compounds is discussed.

Sodium 3,5-bis(hydroxyimino)-1-methyl-2,4,6-trioxocyclohexanide C 7 H 5 N 2 NaO 5 (I) has been isolated as the only product of the reaction of nitrosation of methylphloroglucinol. The structure of the titled compound has been determined from single crystal X-ray diffraction data. The hydrated C 7 H 5 N 2 NaO 5 ·2. (2) to 1.293 Å respectively. In the IR spectrum of I, the sharp absorption band occurred at 1681 cm −1 due to C=O stretching indicating the strong H-interactions. The correlations of theoretical (DFT-B3LYP/aug-cc-pVDZ) and experimental UV-vis absorption spectra in neutral and alkaline ethanolic solutions showed the existence of hydroxyimino-nitroso tautomerism while ionization of I.

For Abstract see ChemInform Abstract in Full Text.

New perinone dyes for bulk dyeing synthetic polymers were synthesized. The synthesized dyes are characterized by high thermal stability. The possibility of dyeing Macrolon 28/08 polycarbonate with some of the synthesized dyes was investigated. It was shown that the dyes were uniformly distributed in the bulk of the polymer. It was found that incorporation of a perinone dye containing a pyridine radical in the polycarbonate during formation increases the glass transition temperature, decreases thermooxidative degradation of the polymer, and yields films with elevated physicomechanical indexes.Dyeing with most synthetic dyes from aqueous solutions with the usual methods involves important difficulties due to their hydrophoby. An alternative approach is to dye polymers in bulk, which increases the stability and uniformity of dyeing the fibres and thus improves their quality. Bulk dyeing of fibres made from polymer melts requires use of thermostable dyes compatible with the polymer matrix which are reasonably priced and provide a wide coloristic range. However, the assortment of such dyes is limited.The so-called perinone dyes, synthesized by the reaction of ortho-or peridicarboxylic acids, tetracarboxylic acids, or the corresponding anhydrides with aromatic ortho-or peridiamines satisfy the requirements listed above [1, 2]. We developed a method for fabricating this type of dye which is distinguished by the fact that an anhydride group is preserved in the structure of the dye [3]: O O O O O O N Ar N O O O O H 2 N -Ar -NH 2 + 3 O O O O O O O O O O N Ar N Ar = Ar = 1 2 2 Ar = 1, 3The presence of the anhydride group allows further chemical modification of the molecule to obtain an assortment of dyes with a new set of properties.We investigated the thermal stability of perinone dyes obtained by reacting dyes of 1-3 structure with aromatic and heterocyclic amines, aliphatic and aromatic alcohols, and resorcin.

The reaction of 4-(3,4-dimethoxyphenyl)-5-aminopyrazoles 7A-D with aromatic and heterocyclic aldehydes in strong acidic media (trifluoroacetic or formic acid) has been studied. The initial azomethine derivatives 8 undergo cyclization similar to the Pictet-Spengler condensation to form the intermediate 4,5-dihydroisoquinolines 9 which readily dehydrogenate giving 5-aryl(heteroaryl)-pyrazolo[3,4-c]isoquinoline derivatives 10 as the final products. Whereas for benzaldehyde and its derivatives this one-pot synthesis presents a convenient general route to 5-aryl-pyrazolo[3,4-c]isoquinolines 10, in the case of heterocyclic aldehydes the product structure varies markedly with the structure of the aldehyde used: (i) 3-pyridyl-, 3-quinolyl-, 3-thienyl-, and 1,2,3-thiadiazolyl-5-carboxaldehydes give 5-heteroarylpyrazolo[3,4-c]isoquinolines; (ii) 1-methylbenzimidazolyl-2-carboxaldehyde gives only intermediate azomethine 8Dh, which does not cyclize; (iii) 1-R-3-indolylcarboxaldehydes (R = H, CH3, CH2Ph) eliminate the heteroaryl fragment resulting in 5-unsubstituted pyrazolo[3,4-c]isoquinolines 11. Thienyl-2-carboxaldehyde reacts by both pathways (i) and (iii) depending on the reaction conditions. The single crystal X-ray structures for 10Dj, 10Cd and 11D provide confirmation of the different types of products formed in these reactions. Mechanisms which explain these transformations are presented.

No abstract

No abstract

No abstract