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The reaction between 1-aryl-3,4-dihydroisoquinolines and monocyclic anhydrides was studied for the first time. The method is the first one-step route to previously unknown angularly-aryl substituted racemic [1,4]thiazino[3,4-a]isoquinoline derivatives with trans configuration. It was found that electron-withdrawing substituents in the p-position of the aryl group in the starting 3,4-dihydroisoquinoline led to higher yields and shorter reaction times, which is contrary to previous observations for the reactions of homophthalic anhydride and similar acyclic N-arylmethanimines.

Tautomerization of 2-phenylimidazolecarbaldehydes has not been studied in detail so far, although this process is a well-known phenomenon for imidazole derivatives. That is why we focus our study on a series of 2-phenylimidazolecarbaldehydes and their parent alcohols that were synthesized and studied by detailed 1H and 13C NMR in solution and in the solid state. The apparent problem is that the fast tautomerization impedes the full structural description of the compounds by conventional 13C NMR measurements. Indeed, the 13C NMR spectra in solution exhibit poor resolution, and in most cases, signals from the imidazole ring are not detectable. To avoid this problem, we used 13C CP-MAS NMR as an alternative spectroscopic method for unambiguous spectroscopic characterization of the studied series of 2-phenylimidazoles. The data were analyzed in combination with quantum chemical DFT-GIAO methods by considering the tautomerization process and the intermolecular interactions. The DFT (B3LYP/6-31G(d,p)) calculations allowed to identify and suggest the preferred tautomer in the gas phase and in DMSO solvent, which for alcohols are (2-phenyl-1H-imidazol-4-yl)methanol and its analogs, and for the aldehydes are the 2-phenyl-1H-imidazole-5-carbaldehydes. The gas-phase calculated energy differences between the two possible tautomeric forms are in the range 0.645&ndash, 1.415 kcal/mol for the alcohols and 2.510&ndash, 3.059 kcal/mol for the aldehydes. In the DMSO solvent, however, for all compounds, the calculated energy differences go below 1.20 kcal/mol. These data suggest that both tautomeric forms of the studied 2-phenylimidazoles can be present in solution at room temperature. Our data from detailed 2D NMR measurements in the solid state (1H-13C HETCOR and 1H-1H double-quantum coherence MAS NMR) suggested that also in the solid state both tautomers coexist in different crystalline domains. This fact does not obscure the 13C CP-MAS NMR spectra of the studied 2-phenyl substituted imidazoles and suggests this spectroscopic method as a powerful tool for a complete structural description of tautomeric systems with aromatic conjugation.

The growing advancement in nuclear medicine challenges researchers from several different fields to integrate imaging and therapeutic modalities in a theranostic radiopharmaceutical, which can be defined as a molecular entity with readily replaceable radioisotope to provide easy switch between diagnostic and therapeutic applications for efficient and patient-friendly treatment of diseases. For such a reason, the diagnostic and therapeutic potential of all five medical radionuclides of copper have thoroughly been investigated as they boost the hope for development of successful radiotheranostics. To facilitate the mutual understanding between all different specialists working on this multidisciplinary field, we summarized the recent updates in copper-based nuclear medicine, with specific attention to the potential theranostic applications. Thereby, this review paper is focused on the current achievements in the copper-related complementary fields, such as synthetic and nuclear chemistry, biological assessment of radiopharmaceuticals, design and development of nanomaterials for multimodal theranostic implications. This work includes: i) description of available copper radionuclide production methods; ii) analyses of the synthetic strategies for development of improved copper radiopharmaceuticals; iii) summary of reported clinical data and recent preclinical studies from the last five years on biological applicability of copper radiopharmaceuticals; and iv) illustration of some sophisticated multimodal nanotheranostic agents that comprise several imaging and therapeutic modalities. Significant advancement can be seen in the synthetic procedures, which enables the broader implication of pretargeting approaches via bioorthogonal click reactions, as well as in the nanotechnology methods for biomimetic construction of biocompatible multimodal copper theranostics. All this gives the hope that personalized treatment of various diseases can be achieved by copper theranostics in the near future.

The reaction of 1-[ω-(N-acylated amino)alkyl]-3,4-dihydroisoquinolines (7a, 7b, 7c, 7d, 7e) with homophthalic anhydride (1) leads to the formation of 8-oxo-13a-[(N-acylated amino)alkyl]-8H-dibenzo[a,g]quinolizine-13-carboxylic acids (8a–e) with predomination of cis diastereomers, together with small amount of trans-8a. cis-13a-[(N-Cbzaminomethyl)]-8-oxo-dibenzoquinolizine-13-carboxylic acid (cis-8a) cyclized to the unknown dibenzo[a,g]pyrrolo[3,4-i]quinolizinedione (10) upon moderate heating in methanol.

The reaction of succinic anhydride and N-benzylidene-benzylamine gave rise to the corresponding substituted trans-5-oxopyrrolidine-3-carboxylic acid, which was transformed stereoselectively into two series of compounds. The first one consists of carboxamides, and the second one includes aminomethyl derivatives. The compounds prepared incorporate both a pyrrolidinone part and other nitrogen containing heterocyclic fragments of pharmacological interest.

A novel method for the preparation of 3-(2-hydroxyethyl)-2-methylbenzothiazolium bromide was developed. It consists of heating of 2-methylbenzothiazole, 2-bromoethanol and ethoxyethanol for 2 h. On the next day the precipitate was filtered and air dried.

The reaction between glutaric anhydride (1) and N-benzylidenebenzylamine (3) was studied in detail by 1H NMR spectroscopy under different reaction conditions. The major product was (±)-trans-1-benzyl-6-oxo-2-phenylpiperidine-3-carboxylic acid (2), which was converted into new substituted piperidin-2-ones via transformations of the carboxylic group. The final products are expected to possess pharmaceutical activities, and the relevant screenings are in course.