Capillary gas chromatography of aromatic bicyclic and tricyclic spiro ketones

Summary The separation of some aromatic bicyclic and tricyclic spiro ketones on fused silica capillary columns coated with polydimethylsiloxane, cyanopropylmethylsiloxane and poly(ethylene glycol) stationary phases was investigated. Retention indices were determined at two temperatures in order to enable understanding of the compounds’ chromatographic behaviour. The respective standard deviation values were 0.8, 0.5 and 0.3 index units. The influence of the polarity of the stationary phases on the chromatographic retention of these cyclic spiro ketones is discussed.     

N-Hydroxyhomoazaadamantanone and its complexes with dioxo-molybdenum(VI) and copper(II): synthesis and structure

A hydroxamic acid of a new type, N-hydroxyhomoazaadamantanone (HL), has been synthesized, combining several structure peculiarities: cage skeleton, heterocyclicity, and rigidly fixed cis-orientation of the oxygens of the hydroxamate fragment of the molecule. Complexes of HL with dioxo-molybdenum(VI) ((MoO₂LC₂H₅OH)₂O) and copper(II) (CuL₂) have been synthesized. All compounds were characterized by IR and ¹H NMR spectroscopy. X-ray structural analyses of N-hydroxyhomoazaadamantanone hydrochloride and the coordination compounds have been carried out.     

Preparation of triazolobenzodiazepine derivatives as Vasopressin V1a antagonists

This Letter describes the synthesis of a number of fused tricyclic and bicyclic triazolobenzodiazepines for the Vasopressin V1a antagonist programme.     

Optimum TLC system for identification of phenothiazines and tri- and tetracyclic antidepressants

The TLC separation of twelve drugs from three pharmaceutical groups: phenothiazines and tri and tetracyclic antidepressants is presented. Three kinds of eluents and two types of solid phases (RP 18 and Silica gel 60) were used. The composition of mobile phases was optimized by the Simplex method. In the basic optimization criterion the differences betweenR _f values of the spots corresponding to individual drugs were taken into account. An auxiliary criterion was based on the colour of the spots, which were developed with appropriate reagents. The experimental data obtained during optimization were interpreted using a matrix presentation. In the optimal conditions the differences between positions of the spots enable identification of ten of the examined drugs, but two remained unresolved.Parts of this paper were presented at the 33rd International Congress on Forensic Toxicology, August 27–31, 1995, Thessaloniki, Greece, and the Vth Polish Conference on Analytical Chemistry, September 3–8, 1995, Gdansk     

Synthesis of Acetal Dioxa-Cage Compounds Via Intramolecular Acetalization

An approach to tricyclic acetal dioxa-cage structure ( 1 ) and ( 2 ) involving intramolecular acetalization as the key protocol is reported.     

Non-Aqueous CE Screening Method for 14 Psychotropic Drugs in Whole Blood Samples

Nine tricyclic antidepressants and six phenothiazines were studied together using non-aqueous capillary electrophoresis. The optimum separation conditions were examined by changing such factors as: quantitative composition of the background electrolyte, the salt cation present in the electrolyte and the medium used for dissolution of samples. A number of drugs were also tested as the internal standards for qualitative analysis. The optimum experimental conditions were applied to the identification of the psychotropic drugs spiked to whole blood samples. The repeatability of the identification parameter, ranged from 0.58 to 10.24% RSD calculated in relation to noxiptyline. The evaluated detection limit was 0.15 μg mL⁻¹ for ten drugs and 0.08 μg mL⁻¹ for four drugs.     

The chemistry of 1,3,5-triazacyclohexane complexes 5: cationic zinc(II) alkyl complexes of N-alkylated 1,3,5-triazacyclohexanes and 13-benzyl-1,5,9-triazatricyclo[7.3.1.0]-tridecane

Diethylzinc reacts with hydroperchlorates of N-alkylated 1,3,5-triazacyclohexanes (R₃TAC; R = methyl (Me), benzyl (Bz), isopropyl (ⁱPr)) and with the hydrotetrafluoroborate of 1,3,5-tris-(para-fluorobenzyl)-1,3,5-triazacyclohexane (FBz₃TAC) to give the corresponding cationic zinc ethyl complexes [(R₃TAC)Zn(Et)][X] (X = ClO₄⁻, BF₄⁻). Similar complexes were obtained from diethylzinc treated with [HNMe₂Ph][BF₄] or [HNMe₂Ph][B(C₆F₅)₄](Et₂O) in the presence of R₃TAC (R = Bz, FBz, s-1-phenylethyl (s-PhMeCH)). A product of decomposition of [(Bz₃TAC)Zn(Et)][ClO₄] was analyzed by X-ray diffraction. The structures of [({s-PhMeCH}₃TAC)Zn(Et)][BF₄] an [(FBz₃TAC)Zn(Et)][BF₄] were estimated using nuclear Overhauser enhancement spectroscopy. Protonolysis of diethylzinc with [HNMe₂Ph][BF₄] in the presence of 13-benzyl-1,5,9-triazatricyclo[7.3.1.0^5,13]-tridecane (BzTATC) yielded the complex [(BzTATC)Zn(Et)][BF₄].     

Synthesis, characterization and complexation studies of some novel cyclophane amides and sulfonamides

A series of tricyclic tetraamides have been synthesized and were characterized from spectral and XRD studies. XRD studies revealed that the pyridine-based tricyclic cyclophane amide exists with twisted phenyl rings. All the cyclophane compounds form charge-transfer (CT) complexes with TCNQ. Metal ion complexation studies show that the cyclophane amides are more selective towards Cu(II) ions rather than Ni(II) and Cd(II) ions.     

Microextraction by packed sorbent followed by ultra high performance liquid chromatography for the fast extraction and determination of six antidepressants in urine

The growing use of antidepressants in recent years has led to their increasing presence in forensic analyses. In this work, microextraction by packed sorbent followed by ultra‐performance liquid chromatography with photodiode array detection provided a fast method for determining the antidepressants mirtazapine, venlafaxine, escitalopram, fluoxetine, fluvoxamine, and sertraline in human urine. The microextraction conditions (viz., type of sorbent, number of draw–eject extraction cycles or strokes, sample volume and pH, and type and volume of washing solution and eluent) were optimized by using an experimental design. The ensuing analytical method was validated in terms of linearity (25–1000 ng/mL urine), limit of detection (lower than 7.1 ng/mL), limit of quantification (25 ng/mL), precision (4.7–15.1% as relative standard deviation), and accuracy (80.4–126.1% as mean recovery for four replicate determinations). The proposed method allowed the six target antidepressants to be determined at concentrations from therapeutic to toxic levels. The application to small volumes (300 μL) of urine afforded fast extraction of the analytes and provided results on a par with those of existing clinical and forensic alternatives.     

Ring-opening reactions of triazolo- and tetrazolo-pyridopyrimidines or quinazolines with some carbon nucleophiles

Syntheses of some new pyridotriazolo- and pyridotetrazolopyrimidines are described. These tricyclic systems and tetrazoloquinazoline react with some carbon nucleophiles, generated from compounds with reactive methylene groups, exclusively at position 2 of the fused pyrimidine ring to give the corresponding open-chain enamines.

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Ringöffnungsreaktionen von Triazolo- und Tetrazolo-Pyridopyrimidinen oder Chinazolinen unter dem Einfluß einiger Carbanionen als Nucleophile

Zusammenfassung Die Synthesen von einigen neuen Pyridotriazolo- und Pyridotetrazolopyrimidine werden beschrieben. Diese tricyclischen Verbindungen sowie Tetrazolochinazolin reagieren mit einigen Carbanionen, die aus Verbindungen mit reaktiven Methylengruppen entstehen, ausschließlich in Stellung 2 des kondensierten Pyrimidinringes, wobei die entsprechenden offenkettige Enamine entstehen.