The Synthesis and Absolute Configuration of Enantiomeric Pure (R)- and (S)-3-(piperidin-3-yl)-1H-Indole Derivatives.

This article describes the synthesis of new chiral 3-(piperidin-3-yl)-1H-indole derivatives (R)-10a-c and (S)-11a-c from the corresponding diastereomers: (3R, 2R) and (3S, 2R)-2-[3-(1H-indol-3-yl)-1-piperidyl]-2-phenyl-acetamides (3R, 2R)-4a, (3R, 2R)-6b, (3R, 2R)-8c and (3S, 2R)-5a, (3S, 2R)-7b, (3S, 2R)-9c. Diastereomers were obtained by N-alkylation of derivatives of racemic 3-(piperidin-3-yl)-1H-indoles 1a-c using (S)-2-(4-toluenesulfonyloxy)-phenylacetic amide (S)-II. The same method was applied to obtain (3R, 2S)-methyl-2-[3-(1H-indole-3-yl)-1-piperidyl]-2-phenylacetate (3R, 2S)-2a and (3S, 2S)-methyl-2-[3-(1H-indole-3-yl)-1-piperidyl]-2-phenylacetate (3S, 2S)-3a diastereomers by treating amine 1a with (R)-2-(4-toluenesulfonyloxy)-phenylacetic acid methylester (R)-I. Systematic studies via single crystal X-ray crystallography were used to determine the molecular structure of the racemates 1a-c and the absolute configuration of the enantiomers. The solid racemates 1b and 1c were "true racemates" crystallizing in a centrosymmetric space group, while 1a formed a racemic conglomerate of homoenantiomeric crystals. The absolute configuration was determined for the enantiomeric pairs (R)-10a/(S)-11a, (R)-10b/(S)-11b, and (R)-12c/(S)-13c, as well as for (3S,2S)-3a. Spectra of 1H, 13CNMR, HPLC, and HRMS for diastereomers and enantiomers were consistent with the determined structures.

Synthesis of Novel Pyrido[1,2-c]pyrimidine Derivatives with 6-Fluoro-3-(4-piperidynyl)-1,2-benzisoxazole Moiety as Potential SSRI and 5-HT1A Receptor Ligands.

Two series of novel 4-aryl-2H-pyrido[1,2-c]pyrimidine (6a-i) and 4-aryl-5,6,7,8-tetrahydropyrido[1,2-c]pyrimidine (7a-i) derivatives were synthesized. The chemical structures of the new compounds were confirmed by 1H and 13C NMR spectroscopy and ESI-HRMS spectrometry. The affinities of all compounds for the 5-HT1A receptor and serotonin transporter protein (SERT) were determined by in vitro radioligand binding assays. The test compounds demonstrated very high binding affinities for the 5-HT1A receptor of all derivatives in the series (6a-i and 7a-i) and generally low binding affinities for the SERT protein, with the exception of compounds 6a and 7g. Extended affinity tests for the receptors D2, 5-HT2A, 5-HT6 and 5-HT7 were conducted with regard to selected compounds (6a, 7g, 6d and 7i). All four compounds demonstrated very high affinities for the D2 and 5-HT2A receptors. Compounds 6a and 7g also had high affinities for 5-HT7, while 6d and 7i held moderate affinities for this receptor. Compounds 6a and 7g were also tested in vivo to identify their functional activity profiles with regard to the 5-HT1A receptor, with 6a demonstrating the activity profile of a presynaptic agonist. Metabolic stability tests were also conducted for 6a and 6d.

Synthesis and biological investigation of new equatorial (ß) stereoisomers of 3-aminotropane arylamides with atypical antipsychotic profile.

A series of novel 3ß-aminotropane derivatives containing a 2-naphthalene or a 2-quinoline moiety was synthesised and evaluated for their affinity for 5-HT1A, 5-HT2A and D2 receptors. Their affinity for the receptors was in the nanomolar to micromolar range. p-Substitution (6c, 6f, 6i, 6l, 6o), as well as substitution with chlorine atoms (6g, 6h, 6i), led to a significant increase in binding affinity for D2 receptors with compounds 6f (Ki=0.6nM), 6c and 6i (Ki=0.4nM), having the highest binding affinities. m-Substituted derivatives were the most promising ligands in terms of 5-HT2A receptor binding affinity whereas 2-quinoline derivatives (10a, 10b) displayed the highest affinity for 5-HT1AR and were the most selective ligands with Ki=62.7nM and Ki=30.5nM, respectively. Finally, the selected ligands 6b, 6d, 6e, 6g, 6h, 6k, 6n and 6o, with triple binding activity for the D2, 5-HT1A and 5-HT2A receptors, were subjected to in vivo tests, such as those for induced hypothermia, climbing behaviour and the head twitch response, in order to determine their pharmacological profile. The tested ligands presented neither agonist nor antagonist properties for the 5-HT1A receptors in the induced hypothermia and lower lip retraction (LLR) tests. All tested compounds displayed antagonistic activity against 5-HT2A, with 6n and 6o being the most active. Four (6b, 6k, 6n and 6o) out of eight tested compounds could be classified as D2 antagonists. Additionally, evaluation of metabolic stability was performed for selected ligands, and introduction of halogen atoms into the benzene ring of 6h, 6k, 6n and 6o improved their metabolic stability. The project resulted in the selection of the lead compounds 6n and 6o, which had antipsychotic profiles, combining dopamine D2-receptor and 5-HT2A antagonism and metabolic stability.

Model structure-activity relationship studies of potential tropane 5HT1A, 5HT2A, and D2 receptor ligands.

The two-stages studies of structure-activity relationship for model ligands of 5HT1A, 5HT2A, and D2 receptors were performed. On the first stage, the pharmacophores of two potential ligands of known in vitro binding to 5HT1A, 5HT2A, D2 receptors and model pharmacophore of strongly interacting D2 receptor ligands were found and their parameters were related to affinity data. The analyzed parameters were hydrophobic, hydrophilic, aromatic, donor and acceptor of proton centers. The geometry of spatial distribution of these properties was also investigated in comparative analysis. The studied, model compounds were two 3ß-acylamine derivatives of tropane. The second stage includes docking of studied compounds to D2 receptor model and the comparison of its quality with in vivo binding data. The obtained results are consistent with in vitro binding data and applied procedure accurate estimates the affinity of potential ligands to D2 receptors.

Relationship between selenium accumulation and mycelial cell composition in Lentinula edodes (Berk.) cultures.

It was postulated that fractions enriched in selenium (Se) isolated from Lentinula edodes mycelium polysaccharide might possess higher biological activity than the non-enriched fractions currently used to treat cancer. In order to obtain Se-enriched mycelial preparations, L. edodes cultures were cultivated in media enriched with sodium selenite. In order to determine whether the concentration of Se in the culture medium affected the biosynthesis and composition of cell wall and cell membrane, concentrations of the exopolysaccharide (EPS), chitin, and sterol (ergosterol) were measured in harvested mycelia. In addition, the relationship between Se accumulation and content of polyphenols and vitamin D(2) in L. edodes mycelium was examined. The effects of Se levels on the mycelium cell composition were determined in culture media enriched with Se at concentrations ranging from 0 to 30 microg/ml. In each culture mycelial growth, total Se and Se distribution were determined between mycelial fractions of different polarity. The EPS, polyphenolics, and ergosterol content in harvested mycelia rose in proportion to Se concentration in the culture medium. The chitin content in mycelia increased with Se concentrations in the range 0-5 microg/ml, but at higher concentrations chitin levels decreased. Data showed that Se in culture medium exerted potent effects on the composition of the mushroom cell wall and semipermeable membrane, and on the content of polyphenolics that are involved in detoxification processes. Our findings indicate the optimal concentration of Se required in the culture medium for maximal yield of immunostimulatory-active selenated exopolysaccharides.

Understanding performance of 3D-printed sorbent in study of metabolic stability.

Metabolic stability tests are one of the fundamental steps at the preclinical stages of new drug development. Microsomes, used as a typical enzymatic model of liver biotransformation, can be a challenging matrix for analytical scientists due to a high concentration of cellular proteins and membrane lipids. In the work, we propose a new procedure integrating biotransformation reaction with SPME-like protocol for sample clean-up. It is beneficial to increase the overall quality of results in contrary to the typical protein precipitation approach. A set of ten arylpiperazine analogs, six of which are considered promising drug candidates (and four are accepted drugs) were used as a probe to assess the goodness of the newly proposed approach. In order to promote an efficient extraction protocol, a new, miniaturized shape of a sorbent, suitable to perform the extraction in 100 µL of the sample has been designed. Termination of the biotransformation process by protein denaturation with hot water was additionally evaluated. A quantitative structure-property relationship (QSPR) study using Orthogonal Partial Least Squares (OPLS) technique to reveal insights to the sorption mechanism was also performed. The obtained results showed the new 3D-printed sorbent can be an attractive basis for the new sample preparation approach for metabolic stability studies and an alternative for commercially available protocols based on solid-phase microextraction (SPME) or solid-phase extraction (SPE) principles.

Improved simultaneous production of mycelial biomass and polysaccharides by submerged culture of Hericium erinaceum: optimization using a central composite rotatable design (CCRD).

The aim of this study was to optimize the culture medium used for the mycelial growth and production of intracellular polysaccharides (IPS) and exopolysaccharides (EPS) in a submerged culture of Hericium erinaceum. Of the various factors examined, including carbon and nitrogen sources, vitamins, mineral elements, and initial pH, those that proved to have a significant effect were then tested using a 2(4) central composite rotatable design (CCRD). Under the optimal culture conditions, the maximal yield of biomass reached 14.24 +/- 0.45 g l(-1) and was 1.85-fold higher than in the basal medium. The kinetics of EPS biosynthesis in a bioreactor showed that although the highest yield of EPS (2.75 +/- 0.27 g l(-1)) could be obtained on day 8, the process of biosynthesizing high molecular weight polysaccharides proceeded until the depletion of the carbon source in the medium (after 14 days of cultivation). Our results could be very helpful in the large-scale production of bioactive polysaccharides from H. erinaceum.

Molecular Docking Supplements an In vitro Determination of the Leading CYP Isoform for Arylpiperazine Derivatives.

BACKGROUND: Molecular docking has often been used before to calculate in silico affinity of drugs towards their molecular target, but not to estimate leading CYP isoform responsible for metabolism of studied compounds. OBJECTIVE: The aim of this study is to present molecular docking as a valid alternative for costly in vitro studies resulting in estimation of leading CYP isoform. METHODS: In vitro part was based on incubations of studied compounds with isolated CYP3A4 isoform followed by LC-MS analysis. The in silico stage consisted of docking three-dimensional models of the studied compounds with a three-dimensional model of the leading metabolizing isoform (CYP3A4), which was designated during the in vitro part of the study. XenoSite P450 metabolism prediction was also used to predict sites of metabolism and calculate probability values. RESULTS: The calculated affinities showed a clear similarity when the in vitro results were compared with the calculated in silico affinity values. XenoSite CYP3A4 metabolism probability values also confirm significant participation of CYP3A4 in metabolism of studied compounds. CONCLUSION: Both molecular docking and XenoSite P450 metabolism prediction provide data that stands in agreement with in vitro studies, granting a more detailed spectrum on predicting CYP3A4 metabolism, and presenting molecular docking as a promising tool to cut costs and increase effectiveness in early drug development stages.

Synthesis of novel pyrido[1,2-c]pyrimidine derivatives with rigidized tryptamine moiety as potential SSRI and 5-HT1A receptor ligands.

The study enabled obtaining a number of new derivatives of 4-aryl-pyrido[1,2-c]pyrimidine 9.1-9.27 having conformationally restricted tryptamine moiety. In vitro studies (RBA) have shown that derivatives 9.1, 9.2, 9.4, 9.7, 9.9, 9.14 and 9.27 exhibit high affinity to molecular targets 5-HT1A receptor and SERT protein. In general, compounds with an unsubstituted or a para-substituted benzene ring of the pyrido[1,2-c]pyrimidine residue in the terminal part were characterized by higher binding ability, which can be justified by the greater flexibility of the structure. For the selected compounds 9.1, 9.7, 9.9 and 9.27, further in vitro, in vivo and metabolic stability tests were performed. The in vitro studies in the extended receptor profile (D2, 5-HT2A, 5-HT6 and 5-HT7) indicated their selectivity toward the 5-HT1A receptor and SERT protein. The in vivo studies (8-OH-DPAT-induced hypothermia in mice, FST) revealed that the compound 9.1 has the properties of presynaptic agonist of the 5-HT1A receptor, and compound 9.7 demonstrated the properties of a presynaptic antagonist of the 5-HT1A receptor. Metabolic stability studies, in turn, showed that compounds 9.1, 9.7 and 9.9, having an unsubstituted indole residue, were more resistant to biotransformation reactions of the first pass phase than was compound 9.27 containing a 5-methoxy-substituted indole residue. The obtained results allowed further optimization of the structure.

Synthesis of new 5,6,7,8-tetrahydropyrido[1,2-c]pyrimidine derivatives with rigidized tryptamine moiety as potential SSRI and 5-HT1A receptor ligands.

Extended studies in the 4-aryl-pyrido[1,2-c]pyrimidine group resulted in 27 new compounds (10.1-10.27), 5,6,7,8-tetrahydropyrido[1,2-c]pyrimidine derivatives. In vitro tests (RBA) were carried out for 10.1-10.27 compounds in order to determine their affinity to 5-HT1A receptor and SERT protein. 10.1-10.3, 10.6, 10.7, 10.16 and 10.27 compounds had high binding ability to both molecular targets (5-HT1A Ki = 8-87 nM; SERT Ki = 8-52 nM). For these compounds (10.1-10.3, 10.6, 10.7, 10.16, 10.27) further in vitro, in vivo and metabolic stability tests were performed. In vitro studies in the extended receptor profile (D2, 5-HT2A, 5-HT6 and 5-HT7) showed their selectivity towards 5-HT1A receptor and SERT protein. In vivo tests revealed that compounds 10.7 and 10.16 had the properties of presynaptic antagonists of the 5-HT1A receptor. The redesign of the 2H-pyrido[1,2-c]pyrimidine residue present in the terminal part towards 5,6,7,8-tetrahydropyrido[1,2-c]pyrimidine resulted in the improved metabolic stability and enhanced affinity to both molecular targets (5-HT1A-R and SERT) compared to the precursors.

Synthesis and biological evaluation of new multi-target 3-(1H-indol-3-yl)pyrrolidine-2,5-dione derivatives with potential antidepressant effect.

A series of novel 3-(1H-indol-3-yl)pyrrolidine-2,5-dione derivatives were synthesised and evaluated for their 5-HT1A/D2/5-HT2A/5-HT6/5-HT7 receptor affinity and serotonin reuptake inhibition. Most of the evaluated compounds displayed high affinities for 5-HT1A receptors (e.g., 4cKi = 2.3 nM, 4lKi = 3.2 nM). The antidepressant activity of the selected compounds was screened in vivo using the forced swim test (FST). The results indicate that compound MW005 (agonist of the pre- and postsynaptic 5-HT1A receptor) exhibited promising affinities for the 5-HT1A/SERT/D2/5-HT6/5-HT7 receptors and showed an antidepressant-like activity in the FST model.

Synthesis of a new scaffold: the 7H,8H-pyrimido[1,6-b]pyridazin-6,8-dione nucleus.

This paper describes a modified method of preparation of a number of alpha-aryl-alpha-(pyridazin-3-yl)-acetonitriles via the C-arylation reaction of the corresponding carbanionsof phenylacetonitriles using 3-chloropyridazine derivatives. KOH and DMSO were used inthe deprotonation process, which made the reaction very simple and safe to perform.Nitriles were obtained in the hydrolysis reaction to the corresponding alpha-aryl-alpha-(pyridazin-3-yl)-acetamide derivatives, which were next subjected to cyclization to afford the finalproducts. A number of new derivatives of 7H,8H-pyrimido[1,6-b]pyridazin-6,8-dione weresynthesized in the cyclocondensation reaction of respective alpha-aryl-alpha-(pyridazin-3-yl)-acetamides with diethyl carbonate in the presence of EtONa. The structure andcomposition of the new compounds were confirmed by IR, (1)H- and (13)C- NMR analysesand by elemental C, H and N analysis.

CoMFA methodology in structure-activity analysis of hexahydro- and octahydropyrido[1,2-c]pyrimidine derivatives based on affinity towards 5-HT1A, 5-HT2A and alpha1-adrenergic receptors.

Structural features of the pyrido[1,2-c]pyrimidine derivatives with arylpiperazine moiety and their affinities towards 5-HT1A, 5-HT2A and alpha1-adrenergic receptors were analyzed using the CoMFA procedure. On the basis of 3D-QSAR models for the 5-HT2A and alpha1-adrenergic receptors, four compounds with expected better affinity/selectivity were proposed and synthesized. The affinities obtained confirm experimentally the usefulness of CoMFA models. Our results suggest that active conformations adopted by the studied molecules when interacting with the receptors are neutral instead of the protonated ones.

Synthesis of new hexahydro- and octahydropyrido[1,2-c]pyrimidine derivatives with an arylpiperazine moiety as ligands for 5-HT1A and 5-HT2A receptors. Part 4.

New 4-aryl-2H-pyrido[1,2-c]pyrimidine-1,3-dione derivatives of arylpiperazine (6-18) were prepared and evaluated in vitro for their affinity for 5-HT1A, 5-HT2A, and alpha1 receptors. The influence of ortho substitution in the phenyl ring, substitution at position 4 of the pyrido[1,2-c]pyrimidine system, and its unsaturation degree were explored. The tested compounds showed high affinity for the 5-HT1A receptor (Ki = 1.3-79.2 nM) and moderate to low affinity for the 5-HT2A (Ki = 51.7-1405 nM) and alpha1 receptors (Ki = 19.7-382.3 nM). Compounds 8 and 10 showed the highest 5-HT1A receptor affinity (Ki = 1.3 and 2.2 nM, respectively) and were 37- and 35.9-fold, respectively, more selective in relation to alpha1 adrenoreceptors.

Prediction of overall in vitro microsomal stability of drug candidates based on molecular modeling and support vector machines. Case study of novel arylpiperazines derivatives.

Other than efficacy of interaction with the molecular target, metabolic stability is the primary factor responsible for the failure or success of a compound in the drug development pipeline. The ideal drug candidate should be stable enough to reach its therapeutic site of action. Despite many recent excellent achievements in the field of computational methods supporting drug metabolism studies, a well-recognized procedure to model and predict metabolic stability quantitatively is still lacking. This study proposes a workflow for developing quantitative metabolic stability-structure relationships, taking a set of 30 arylpiperazine derivatives as an example. The metabolic stability of the compounds was assessed in in vitro incubations in the presence of human liver microsomes and NADPH and subsequently quantified by liquid chromatography-mass spectrometry (LC-MS). Density functional theory (DFT) calculations were used to obtain 30 models of the molecules, and Dragon software served as a source of structure-based molecular descriptors. For modeling structure-metabolic stability relationships, Support Vector Machines (SVM), a non-linear machine learning technique, were found to be more effective than a regression technique, based on the validation parameters obtained. Moreover, for the first time, general sites of metabolism for arylpiperazines bearing the 4-aryl-2H-pyrido[1,2-c]pyrimidine-1,3-dione system were defined by analysis of Q-TOF-MS/MS spectra. The results indicated that the application of one of the most advanced chemometric techniques combined with a simple and quick in vitro procedure and LC-MS analysis provides a novel and valuable tool for predicting metabolic half-life values. Given the reduced time and simplicity of analysis, together with the accuracy of the predictions obtained, this is a valid approach for predicting metabolic stability using structural data. The approach presented provides a novel, comprehensive and reliable tool for investigating metabolic stability, factors that affect it, and the proposed structures of metabolites at the same time. The performance of the DFT-SVM-based approach provides an opportunity to implement it in a standard drug development pipeline.

A method for rapid screening of interactions of pharmacologically active compounds with albumin.

We determine the association constants for ligand-protein complex formation using the flow injection method. We carry out the measurements at high flow rates (F=1 mL min(-1)) of a carrier phase. Therefore, determination of the association constant takes only a few minutes. Injection of 1 nM of the ligand (10 µL of 1 µM concentration of the ligand solution) is sufficient for a single measurement. This method is tested and verified for a number of complexes of selected drugs (cefaclor, etodolac, sulindac) with albumin (BSA). We obtain K=4.45×10(3) M(-1) for cefaclor, K=1.00×10(5) M(-1) for etodolac and K=1.03×10(5) M(-1) for sulindac in agreement with the literature data. We also determine the association constants of 20 newly synthesized 3ß- and 3α-aminotropane derivatives with potential antipsychotic activity--ligands of 5-HT1A, 5-HT2A and D2 receptors with the albumin. Results of the studies reported here indicate that potential antipsychotic drugs bind weakly to the transporter protein (BSA) with K≈10(2)-10(3) M(-1). Our method allows measuring K in a wide range of values (10(2)-10(9) M(-1)). This range depends only on the solubility of the ligand and sensitivity of the detector.

Novel 4-aryl-pyrido[1,2-c]pyrimidines with dual SSRI and 5-HT1A activity. Part 4.

This project describes the synthesis, pharmacological and pharmacodynamic tests on two series of novel derivatives of 2H-pyrido[1,2-c]pyrimidine with potential binary binding to 5-HT1A receptors and SSRI + serotonin transporters. The influence of piperidinyl-indole (8.1-8.7) and tetrahydropyridinyl-indole (8.8-8.32) residues and indole 5-position substituents (R3 = Br, Cl, F) present in the pharmacophore element of ligands on their binding to both molecular targets was tested. A considerable impact of piperidinyl-indole residue on binding to both targets was confirmed and compounds with a high binding affinity were identified: Ki 5-HT1A = 12.4 nM; Ki SERT = 15.6 nM 8.1; Ki 5-HT1A = 5.6 nM; Ki SERT = 20.7 nM 8.7, while the presence of a tetrahydropyridinyl-indole residue was found to reduce the affinity of ligands to 5-HT1AR. The presence of chlorine (R3) in this series resulted in a notable reduction in binding to both targets (5-HT1A and SERT). Selected compounds had their metabolic stability in a first-pass test (human liver microsomes, NADPH) determined in vitro, and R1 and R2 substituents present on the terminal residue of pyrido[1,2-c]pyrimidine were recognized as having an impact on stability.

Novel 4-aryl-pyrido[1,2-c]pyrimidines with dual SSRI and 5-HT(1A) activity. Part 5.

A series of novel 4-aryl-pyrido[1,2-c]pyrimidine derivatives containing a 1-(2-quinoline)piperazine moiety was synthesized. The chemical structure of new compounds was confirmed by FT-IR, (1)H NMR, (13)C NMR and HRMS spectra as well as elemental analysis. Affinity of the novel pyrido[1,2-c]pyrimidine derivatives for 5-HT1A, 5-HT2A receptors and serotonin transporter (SERT) was evaluated in an in vitro radioligand binding assay. Tested compounds showed moderate to high affinity for 5-HT1AR and SERT and low affinity for 5-HT2AR. Selected ligands were subjected to in vivo tests, such as induced hypothermia and the forced swimming test in mice, which determined presynaptic agonistic activity of the ligands 8d, 8e, 9d and 9e and presynaptic antagonistic activity of the ligands 8a, 8b, 9a, 9b. Additionally, metabolic stability evaluation was performed for selected ligands, proving that a para-substitution in the 4-aryl-pyrido[1,2-c]pyrimidine moiety leads to an increase in stability, whereas a substitution in the ortho-position lowers the stability.

Synthesis of new hexahydro- and octahydropyrido[1,2-c]pyrimidine derivatives with an arylpiperazine moiety as ligands for 5-HT1A and 5-HT2A receptors.

Synthesis applied to prepare compounds 5-15 and 17-22 discussed in this paper has been presented in Scheme 1. Multi-stage preparation techniques were used to obtain 4-aryl-hexahydro 1-4 and (R,R) and (S,S) 4-aryl-octahydropyrido[1,2-c]pyrimidine-1,3-dione (16) derivatives, being the starting compounds for further modification. N-Alkylation of the imide group in compounds 1-4 and 16 followed, using 1,4-dibromobutane to yield monobromobutyl derivatives 5-8 and 17. Subsequent condensation of those compounds with appropriate 1-aryl or 1-heteroarylpiperazine led to the final hexahydro- 9-15 and octahydro- 18-22 pyrido[1,2-c]pyrimidine-1,3-dione derivatives. The final products were subjected to screening test to elucidate the affinity to 5-HT1A and 5-HT2A receptors.

Synthesis and conformation analysis of 3-substituted derivatives of 1H,3H-pyrido[2,3-d] pyrimidin-4-one of expected depressive nervous system. Part III.

Four series of new 1-aryl (heteroaryl) piperazinylacetyl derivatives of 1H,3H-pyrido[2,3-d] pyrimidin-4-one VIIa-o were synthesised. Substrates for the synthesis of VIa-d were obtained from the respective 3H-pyrido[2.3-d]pyrimidines IVa-d in the reaction with NaBH4. Compounds VIa-d were prepared by chloroacetylation. The obtained 1-chloroacetyl derivatives in the reaction with respective aryl (heteroaryl) piperazine formed 1-aminoacetyl derivatives of 2-phenyl-1 H.3H-pyrido[2.3-d]pyrimidin-4-one compounds VII1a-n. The structure ol compounds was analysed by 1H, 13C NMR spectroscopy.