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Amides are usually prepared using amines and acyl halides, which often implies a two-step procedure. Alternatively, coupling reagents can be used in a single-step reaction with good yields, which seems to be suitable for organic chemistry laboratory classes. This work was designed to synthesize N-hexylcinnamamide through a one-step reaction from cinnamic acid using the coupling reagent benzotriazol-1-yloxytri(pyrrolidino)phosphonium hexafluorophosphate (PyBOP). The purification of N-hexylcinnamamide, using various laboratory techniques, as well as its structural elucidation by spectroscopic methodologies, is also addressed. In addition, the theoretical partition coefficient (log P) values of N-hexylcinnamamide and of cinnamic acid are predicted. The proposed experiment is developed in three laboratory classes and is planned for second-year undergraduate students. In summary, it is expected that students broaden their knowledge about amide synthesis, laboratory techniques, and spectroscopic characterization, especially IR and NMR. Besides the pedagogical enhancements, this activity also allows students to be in contact with research work based on the chemical modification of natural products according to a medicinal chemistry approach.

The interaction between sodium salicylate (NaSal) and the two macrocycles 5,11,17,23-tetrakissulfonatomethylene-2,8,14,20-tetra(ethyl)resorcinarene (Na4EtRA) and β-cyclodextrin (β-CD) has been studied by the determination of ternary mutual diffusion coefficients, and spectroscopic and computational techniques. The results obtained by the Job method suggest that the complex formation is given in a 1:1 ratio for all systems. The mutual diffusion coefficients and the computational experiments have shown that the β-CD-NaSal system presents an inclusion process, whereas the Na4EtRA-NaSal system forms an outer-side complex. This fact is also in line with the results obtained from the computational experiments, where the calculated solvation free energy has been found to be more negative for the Na4EtRA-NaSal complex because of the partial entry of the drug inside the Na4EtRA cavity.

Knowledge of mass transport parameters, diffusion, and viscosity of hyaluronic acid (HA) in the presence of cyclodextrins is of considerable importance for areas such as food packaging and drug delivery, among others. Despite a number of studies investigating the functionalization of HA or the corresponding sodium salt by cyclodextrins, only a few studies have reported the effect of cyclodextrins on the mass transport of HA in the presence of these oligosaccharides. Here, we report the tracer binary and ternary interdiffusion coefficients of sodium hyaluronate (NaHy) in water and aqueous β-cyclodextrin solutions. The diffusion behavior of sodium hyaluronate was dependent on the reduced viscosity of NaHy, which, in turn, presented a concave dependence on concentration, with a minimum at approximately 2.5 g dm-3. The significant decrease in the limiting diffusion coefficient of NaHy (at most 45%) at NaHy concentrations below 1 g dm-3 in the presence of β-cyclodextrin, taking water as the reference, allowed us to conclude that NaHy strongly interacted with the cyclodextrin., Fundacao para a Ciencia e a Tecnologia (FCT) through COMPETE Programme (Operational Programme for Competitiveness) [UIDB/QUI/00313/2020]; Ministry of Education, Youth and Sports of the Czech Republic DKRVO [RP/CPS/2022/003]

Metal ions such as cobalt (II) and chromium (III) might be present in the oral cavity, as a consequence of the corrosion of Co-Cr dental alloys. The diffusion of such metal ions into the organism, carried by saliva, can cause health problems as a consequence of their toxicity, enhanced by a cumulative effect in the body. The effect of the chlorhexidine digluconate, which is commonly used in mouthwash formulations, on the transport of these salts is evaluated in this paper by using the Taylor dispersion technique, which will allow an assessment of how the presence of chlorhexidine digluconate (either in aqueous solution or in a commercial formulation) may affect the diffusion of metal ions. The ternary mutual diffusion coefficients of metal ions (Co and Cr) in the presence of chlorhexidine digluconate, in an artificial saliva media, were measured. Significant coupled diffusion of CoCl2 (and CrCl3) and chlorhexidine digluconate is observed by analysis of the non-zero values of the cross-diffusion coefficients, D12 and D21. The observed interactions between metal ions and chlorhexidine digluconate suggest that the latter might be considered as an advantageous therapeutic agent, once they contribute to the reduction of the concentration of those ions inside the mouth.

The transport and association of the dipeptide glycyl-L-phenylalanine (Gly-L-Phen) in solutions containing cyclodextrins are of prime importance given its relevance in different areas, from biochemistry to wastewater treatment. We have investigated the interaction between aqueous Gly-L-Phen and β-cyclodextrin (β-CD) by NMR, DFT calculations in parallel with UV/visible absorption, luminescence spectral measurements and diffusion experiments. Ternary mutual diffusion coefficients of aqueous {Gly-L-Phen + β-CD} solutions have been measured by using the Taylor dispersion technique. The results show that the association of Gly-L-Phen and β-CD has a significant effect on the diffusion coefficients, consistent with an association constant of about 50 to 100, assuming a 1:1 (Gly-L-Phen):(β-CD) stoichiometry. This stoichiometry has been assessed by the continuous variation (Job's plot) method and the association constant was determined by using the Hildebrand-Benesi equation modified for NMR applications. The association constant was estimated to be equal to 40. This association constant is in close agreement with that obtained by fluorescence measurements (K = 43). Additionally, from NMR, detailed structural information on the complex has been obtained. This has been complemented by DFT and TD-DFT studies.

Ethambutol (as its dihydrochloride) is a bacteriostatic drug, which is widely used as part of the Tuberculosis treatment protocol. It can also act as a ligand for various metal ions, such as copper(II), leading to complexes with potentially interesting applications in medicinal and analytical chemistry. The structure of such complexes is relevant to the question of the coordination geometry of the copper(II) ion in aqueous solution. We report a structural study of the 1:1 complex formed between ethambutol (Emb) and copper(II), using visible absorption, multinuclear NMR (1H and 13C), and EPR spectroscopies, and density functional theory (DFT) calculations. These all support a pentacoordinate structure with a distorted square pyramidal geometry involving a central Cu(II) ion coordinated by a tetradentate Emb ligand and one water molecule. The diffusion behaviour of this complex has been studied, and is compared with that of the free ligand by measuring limiting mutual diffusion coefficients for aqueous systems at 25 °C using the Taylor dispersion method. From these results, we have estimated the tracer diffusion coefficient of ethambutol in supporting solutions of copper nitrate and the limiting diffusion coefficients of the 1:1 complex formed between ethambutol and copper ion. By using the Stokes-Einstein equation, the limiting hydrodynamic radii of this complex, Rh, have also been estimated and are compared with the free Emb.

Ternary mutual diffusion coefficients (D11, D22, D12 and D21) measured by the Taylor dispersion method are reported for aqueous solutions of paracetamol (1) in the presence of β-cyclodextrin (β-CD) (2) at 298.15 K and solute concentrations up to 0.050 (mol dm−3). The diffusion of paracetamol and β-CD is coupled, as indicated by non-zero values of the cross-diffusion coefficients, D12 and D21 measuring interactions between the fluxes of the drug and the carbohydrate. The measured ternary diffusion coefficients are in close agreement with the diffusion coefficients predicted by a model assuming a 1:1 (paracetamol):(β-CD) complex. The association constant K = 27 (mol−1 dm3) for the formation of the complex was estimated from the diffusion data.

Cancer pharmacology is often markedly toxic and must be precisely dosed in order to reach the therapeutic bioavailability under strict control. Transport properties are important tools in the process of interpretation and fine-tuning pharmaceutical applications, notably for drugs that have a long record of use and have met their limits of bioavailability. 5–Fluorouracil (5-FU) is one of the most used antineoplastic agents since its discovery in 1957. In this paper, binary mutual diffusion coefficients of 5-fluorouracil, obtained from a Taylor dispersion method setup are reported for aqueous solutions up to 75 mmol. kg1. These data were complemented by viscosity measurements. The overall information allows to compute descriptive parameters and further interpretation on the basis of well-established models. 8E1D-B2A5-3B37 | Luis Manuel Pires Verissimo info:eu-repo/semantics/publishedVersion

This study was undertaken to evaluate the effects of Solanum sisymbriifolium cvs Melody, Pion, Sharp, Sis 4004 and Sis 6001 on potato cyst nematode (PCN), Globodera spp., populations in the field in Portugal, to improve crop protection systems based on trap crops. Two PCN infested fields (Bolho and Barcouco) were selected. Solanum sisymbriifolium root exudates effects on PCN hatching were evaluated by in vitro assays and their susceptibility/resistance to PCN was assessed. Field trials were performed during 2 years using the following rotation: S. tuberosum cv. Desiree followed by S. sisymbriifolium. Solanum sisymbriifolium root exudates promoted hatching of second-stage juveniles (J2). The cultivars tested were resistant to both species of PCN. In both fields, all cultivars had the same behaviour with no statistically significant differences. As S. sisymbriifolium cultivars were resistant to G. rostochiensis and G. pallida populations in Portugal, they can be included in crop rotations and are potential candidates to incorporate in management programs against PCN. Although there were no statistical differences it seems that fallow could be the best strategy to reduce PCN populations faster and this avoids the introduction of an exotic plant that could become a problem.

Ternary mutual diffusion coefficients (Dik) measured by the Taylor dispersion method are reported for aqueous paracetamol + NaOH solutions at 25.00 °C and concentrations up to 0.050 mol dm−3. The coupled diffusion of paracetamol (1) and NaOH (2) is significant, as indicated by the large negative cross-diffusion coefficients. In sodium hydroxide solutions, paracetamol, a weak acid, is partially converted to its sodium salt. To help interpret the results, the measured Dik coefficients are compared with predictions based on Nernst and Nernst-Planck equations for mixed electrolyte solutions. The analysis shows that the diffusion of the paracetamol and sodium hydroxide components is strongly coupled by the electric field (diffusion potential) generated by the ionic concentration gradients.

Ternary mutual diffusion coefficients (D11, D22, D12 and D21) measured by the Taylor dispersion method are reported for aqueous solutions of (NaCl + lactose) at 298.15 K and NaCl concentrations up to 1.00 mol dm−3. The coupled diffusion of NaCl (1) and lactose (2) is significant, as indicated by the large negative cross-diffusion coefficients. In this sense, from the values of these cross-diffusion coefficients a counter-transport of 0.4 mol of NaCl per mol of diffusing lactose is inferred, whereas only 0.02 mol of lactose could be counter-transported by one diffusing mole of NaCl. The main diffusion coefficient data are compared with the binary ones of both pure solutes in water and discussed on the basis of Onsager-Fuoss and Pikal models. From these data and by performing molecular dynamics simulations, it is possible to obtain a better understanding of the effect of sodium chloride on the transport of lactose in aqueous solutions, as well as to assume the importance of the Na+-lactose short-range interaction, competing with the coulomb long-range interaction between the sodium and chloride ions, especially at low concentration of NaCl.

Ternary mutual diffusion coefficients measured by the Taylor dispersion method are reported for aqueous solutions of {ethambutol dihydrochloride (1) + HCl (2)} at 25 °C and various carrier solution compositions. Mutual diffusion coefficients estimated from limiting ionic conductivities using Nernst equations are used to discuss the composition dependence of the measured diffusion coefficients. 1 H NMR studies, combined with DFT calculations, confirm a fully extended conformation for the diprotonated form of the drug present under these conditions, and are consistent with an electrostatic mechanism for the strongly coupled diffusion of diprotonated ethambutol and HCl.

The Taylor dispersion technique has been used for measuring mutual diffusion coefficients of β-cyclodextrin sulfated sodium salt (NaSO 3 βCD) at temperatures (298.15 and 310.15) K and at finite concentrations. These studies have been complemented by density and viscosity measurements. From these experimental results, the hydrodynamic radius R h , and its dependence on the viscosity, diffusion coefficient at infinitesimal concentration, D 0 , ion conductivity of NaSO 3 βCD and the thermodynamic factor, F T , have been estimated, permitting us to have a better understanding of the structure of the aqueous system containing NaSO 3 βCD.

The Taylor dispersion technique was used to measure quaternary diffusion coefficients, 123 D 11 , 123 D 22 , 123 D 33 , 123 D 12 , 123 D 13 , 123 D 21 , 123 D 23 , 123 D 31 , and 123 D 32 , in aqueous solutions of 2-hydroxypropyl-β-cyclodextrin (HP-βCD) + KCl + caffeine (CAF) + water, and 2-hydroxypropyl-β-cyclodextrin (HP-βCD) + KCl + theophylline (THP) + water at T = 310.15 K at different carrier concentrations of 0.002, 0.005 and 0.010 mol · dm −3 , for each solute. The behaviour diffusion of these multicomponent systems and the coupled flows occurring in the solution can be explained on the basis of salting-out effects, as well as the possible interactions between both (cyclodextrin + xantine) or (cyclodextrin + metal ion) interactions, lead us in this way to obtain a better understanding of the structure of these systems.

Experimental mutual diffusion coefficients of potassium chloride, magnesium nitrate, cobalt chloride and beryllium sulphate in aqueous solutions have been compared with those estimated by the Onsager-Fuoss. From the observed deviations, we are proposing a model that allows to estimate the percentages of H 3 O + (aq) resulting of hydrolysis of some ions (i.e. beryllium, cobalt, potassium and magnesium ions), contributing in this way to a better knowledge of the structure of these systems.

Objective:Doctor–patient communication in oncology, particularly concerning diagnostic disclosure, is a crucial factor related to the quality of the doctor–patient relationship and the psychological state of the patient. The aims of our study were to investigate physicians' opinions and practice with respect to disclosure of a cancer diagnosis and to explore potential related factors.Method:A self-report questionnaire developed for our study was responded to by 120 physicians from Coimbra University Hospital Centre and its primary healthcare units.Results:Some 91.7% of physician respondents generally disclosed a diagnosis, and 94.2% were of the opinion that the patient knowing the truth about a diagnosis had a positive effect on the doctor–patient relationship. A need for training about communicating with oncology patients was reported by 85.8% of participants. The main factors determining what information to provide to patients were: (1) patient intellectual and cultural level, (2) patient desire to know the truth, and (3) the existence of family.Significance of results:Our results point to a paradigm shift in communication with cancer patients where disclosure of the diagnosis should be made part of general clinical practice. Nevertheless, physicians still experience difficulties in revealing cancer diagnoses to patients and often lack the skills to deal with a patient's emotional responses, which suggests that more attention needs to be focused on communication skills training programs.

Background Metastatic tumours sometimes present with neuropsychiatric symptoms, however psychiatric symptoms as rarely the first clinical manifestation. Cutaneous melanoma is the third most common cause of brain metastasis, with known risk factors increasing the chance of such central nervous system metastization. Objectives We present a clinical report of delirium as the first clinical manifestation of melanoma brain metastases, illustrating the relevance of an adequate and early differential diagnosis. Methods In addition to describing the clinical case, searches were undertaken in PubMed and other databases using keywords such as “brain metastasis”, “melanoma”, “agitation”, “psychiatric” and “delirium”. Results We here report the case of a 52-year-old female patient evaluated by Liaison Psychiatry after sudden onset of delirium while admitted at the Gastroenterology Department to study a hypothesis of pancreatitis. A head CT scan identified brain metastases, and after further examination, including brain biopsy, melanoma brain metastization was confirmed. Discussion Some of the diagnostic challenges of psychiatric symptoms associated with secondary brain tumours are discussed, underlining the importance of an adequate differential diagnosis when working in Psychiatry Liaison.

Mutual diffusion coefficients (interdiffusion coefficients) of sodium alginate in aqueous dilute solutions, at concentrations from 0.001 to 0.500 g mL−1 and at 298.15 K, alone and in combination with caffeine, using an open-ended conductimetric capillary cell, have been measured. These results are discussed in the light of structural analysis conducted by means of theoretical calculations (molecular mechanics). Based on such results, the equivalent conductance at infinitesimal concentration of the alginate ion in the referred solutions, at 298.15 K, has been estimated. These studies, complemented by some density and viscosity measurements, and carried out at the same range of concentrations, permit us to have a better understanding of the structure of these systems and the thermodynamic behaviour of sodium alginate in different media, that is, improving the know how of the physical and chemical interactions of those two important food chemistry components.

Ternary mutual diffusion coefficients measured by Taylor dispersion method (D11, D22, D12, and D21) are reported for aqueous solutions containing isoniazid and different electrolytes (NaCl, NaOH, or HCl) at T = 298.15 K at different carrier concentrations. These diffusion coefficients have been measured having in mind a better understanding of the structure of these systems and the thermodynamic behaviour of isoniazid in different media. For example, it is possible to make conclusions about the influence of these electrolytes in diffusion of isoniazid, and to obtain information concerning the number of moles of each component transported per mole of the other component driven by its own concentration gradient.

Ternary mutual diffusion coefficients measured by Taylor dispersion method (D11, D22, D12, and D21) are reported for aqueous solutions of 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) + caffeine at T = 298.15 K at carrier concentrations from (0.000 to 0.010) mol · dm−3, for each solute, respectively. These diffusion coefficients have been measured having in mind a better understanding of the structure of these systems and thermodynamic behaviour of caffeine and 2-hydroxypropyl-β-cyclodextrin in solution. For example, from these data it will be possible to estimate some parameters, such as the fraction of associated species HP-β-CD (X1) and caffeine (X2) in this complex, the monomer and dimer fractions, X 2 M and X 2 D , respectively, and the limiting diffusion coefficients of the HP-β-CD, D HPBCD ∘ , of the dimers caffeine entities, D D ∘ , and of those complexes (1:1), D complex ∘ .

Binary mutual diffusion coefficients measured by the Taylor dispersion method are reported for aqueous solutions of α-cyclodextrin (α-CD), 2-hydroxypropyl-α-cyclodextrin (HP-α-CD), and 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) at concentrations from (0.002 to 0.010) mol·dm-3 at temperatures from (298.15 to 312.15) K. The hydrodynamic radius and activation energy for the diffusion of aqueous α-CD, HP-α-CD, and HP-β-CD are calculated from the experimental results. In addition, the Hartley equation and the measured diffusion coefficients are used to estimate activity coefficients for aqueous α-CD, HP-α-CD, and HP-β-CD.

Binary mutual diffusion coefficients (interdiffusion coeffcients) have been measured for aqueous solutions of β-cyclodextrin (β-CD) at concentrations from (0.002 to 0.008) mol·dm-3. The effect of temperature, from (298.15 to 312.15) K, was also analyzed. The concentration dependence of D is discussed on the basis of Hartley's equation. The activation energy for the diffusion process, 18719 J·mol-1, was calculated from data of D at different temperatures. This activation energy is in good agreement with that estimated using Stokes−Einstein equation (18644 J·mol-1). Activity coefficients for aqueous β-CD solutions were also estimated from Hartley equation and experimental D.

Binary mutual diffusion coefficients measured by the Taylor dispersion method, for aqueous solutions of paracetamol (PA) at concentrations from (0.001 to 0.050) mol·dm−3 at T = 298.15 K, are reported. From the Nernst–Hartley equation and our experimental results, the limiting diffusion coefficient of this drug and its thermodynamic factors are estimated, thereby contributing in this way to a better understanding of the structure of such systems and of their thermodynamic behaviour in aqueous solution at different concentrations.

A Taylor dispersion method has been used to measure ternary diffusion coefficients of three-component aqueous systems, D11, D22, D12, and D21, for aqueous solutions of CuCl2−theophiline at temperatures of (298 and 310) K at carrier concentrations from (0.000 to 0.010) mol·dm−3, for each solute, respectively. The results are compared with these obtained for (H2O + CuCl2) and (H2O + 1,3-dimethyl-7H-purine-2,6-dione), also reported here.

A Taylor dispersion method is used to measure ternary multicomponent diffusion coefficients of three-component liquid systems. Ternary mutual diffusion coefficients measured by this method (D11, D22, D12, and D21) are reported for aqueous solutions of β-cyclodextrin (β-CD) + caffeine at 298.15 K at carrier concentrations from (0.000 to 0.010) mol·dm−3, for each solute, respectively. These diffusion coefficients have been measured having in mind a better understanding of the structure of these systems and the thermodynamic behavior of caffeine and cyclodextrin in solution.

In the solid state, the title compound, C15H23NO4, forms centrosymmetric dimers in which individual mol­ecules are linked by intermolecular N—H⋯O hydrogen bonds. The pyrrole ring is planar within 0.004 (9) A.

Diffusion coefficients, thermodynamic and mobility factors of iron salts in aqueous solutions are estimated from Onsager-Fuoss model. The influence of the ion size parameter a, "mean distance of closest approach of ions", determined from different approaches, on the variation of diffusion coefficients with concentration, is also discussed. The aim of this work is to have a better understanding of the structure of these systems and of the thermodynamic behaviour of iron salts in aqueous media.

Mutual diffusion coefficients, D, densities, ρ, and viscosities, η, are reported for aqueous solutions of L-3,4-dihydroxyphenylalanine (L-Dopa) at 298.15K and 310.15K at concentrations from (0.00025 to 0.0075) moldm(-3). The aim of this study is to contribute to a better understanding of the structure of these systems and the thermodynamic behaviour of L-Dopa in solution. Thus, from these experimental data it was possible to estimate some parameters, such as the hydrodynamic radius, Rh, apparent molar volumes, ϕV, and diffusion coefficients at infinitesimal concentration, D(0), essential for a better understanding of disperse systems. From the measured diffusion coefficients, activity coefficients, γ, for aqueous L-Dopa solutions were also estimated by using Nernst-Hartley equation. The effect of the viscosity on the estimated hydrodynamic radius was also studied.

Binary (D) and ternary (D(11), D(22), D(12) and D(21)) mutual diffusion coefficients determined by the Taylor dispersion method are reported for two aqueous systems, pure hydrocortisone (HC/H(2)O) and HC plus HP-β-cyclodextrin (HC/HP-βCD/H(2)O), at T=298.15 K. From these data, some thermodynamic information as well as conclusions about the influence of that carbohydrate in the diffusion of this drug are given.

Binary mutual diffusion coefficients measured by the Taylor dispersion method in two different laboratories (University of Naples, Federico II, Italy, and University of Coimbra, Portugal) are reported for aqueous solutions of isoniazid at concentrations from (0.000 to 0.100) mol·dm−3 and at two temperatures (298.15 and 310.15) K. The hydrodynamic radii for the isoniazid in aqueous solution are calculated from the experimental results. In addition, the Hartley equation and the experimental diffusion coefficients are used to estimate activity coefficients for aqueous isoniazid at both temperatures.

Objective: The main aims of this article are twofold. First, to assess perfectionism dimensions in obsessive-compulsive disorder and eating disorders in comparison with psychiatric control (depression/anxiety) and non-clinical control groups. Second, to examine if perfectionism is specifically related to these different clinical conditions. Method: Thirty-nine outpatients with obsessive-compulsive disorder, 24 outpatients with eating disorders, 65 outpatients with a diagnosis of depression and/or anxiety, and 70 non-clinical participants completed the Portuguese version of the Multidimensional Perfectionism Scale. Results: Compared to non-clinical subjects, individuals of all clinical samples had significantly higher scores on Multidimensional Perfectionism Scale total score, Self-Oriented and Socially-Prescribed Perfectionism. There were no significantly differences in Self-Oriented Perfectionism and Multidimensional Perfectionism Scale total score in all the three clinical samples. Subjects from the eating disorders sample had significantly higher scores of Socially-Prescribed Perfectionism in comparison to obsessive-compulsive disorder and psychiatric control samples. Conclusion: Perfectionism showed to be related with this broad range of psychopathologies. However, the differences between eating disorders versus obsessive-compulsive disorder and psychiatric control on Socially-Prescribed Perfectionism warrant further investigation in order to clarify the specificity of this perfectionism dimension in eating disorders. Descriptors: Personality; Obsessive-compulsive disorder; Eating disorders; Depression; Anxiety

Introduction Thyroid disease may contribute to mental illness, and thyroid dysfunction in psychiatric illness is common. However, the exact mechanism underlying the link between thyroid abnormalities and psychiatry illness is unclear, and the routine use of thyroid tests to assess psychiatric patients remains debatable. There are no specific guidelines about witch tests should be routinely done, however psychiatrists should be aware that thyroid test abnormalities do not always denote thyroid disease, because there are many factors that interfere with these tests at newly admitted psychiatric patients. Aims To review evidence about the clinical utility and cost-effectiveness of thyroid screening in psychiatric inpatients. Methods Searches were undertaken in PubMed and other relevant databases using keywords such as 'thyroid screening', 'psychiatric' and 'inpatients'. Results Recent data suggests that clinical utility of thyroid testing in psychiatric patients is low, but in some subgroups of patients thyroid tests may be useful. In fact, there are few studies of cost-effectiveness of thyroid screening in psychiatric inpatients. Therefore clinicians have to pay attention to indications of request thyroid tests, to the moment of thyroid analyses and that transient nature of abnormal thyroid tests results may be a reflection of multitude of factors. Conclusions The diagnostic yield of thyroid testing in psychiatric patients is low, and recent studies do not fully support routine screening for thyroid dysfunction in psychiatry inpatients. However, the benefits of thyroid screening of newly admitted psychiatric patients should be evaluated in prospective studies.

The title compound, C 15 H 19 NO 3 S, has cis stereochemistry at the ring junction, resulting from an exo intramolecular 1,3-dipolar cycloaddition. It crystallizes as a racemate. The tetrahydrothieno ring has an S-envelope form and the pyrrole ring adopts a half-chair conformation. The amino H atom is shared in a bifurcated intramolecular hydrogen bond between the bare O atoms of the carboxylate and methoxy groups. Cohesion of the structure is achieved through weak intermolecular interactions only.

Taylor dispersion equipment installed at the University of Coimbra for the measurement of diffusion in liquids has been tested to ensure adequate accuracy and precision by measuring mutual diffusion coefficients for binary aqueous solutions of sucrose, glycine, lithium chloride, potassium chloride, and hydrochloric acid at 298.15 K. In addition, binary mutual diffusion coefficients for aqueous solutions of lactic acid (not previously reported in the literature) have been measured at 298.15 and 303.15 K and concentrations up to 0.20 mol-dm-3.

In previous papers, we reported that thiazolidines derived from cysteine methyl ester and aldehydes react with silver carbonate and DBU; the reactions produce transient 1-substituted methyl 2-azadiene-3-carboxylates that act as dienes in the Diels-Alder reaction.1 When we apply the same procedure to the thiazolidines 1a-d we find that the products are isolable cross-conjugated bis(enamines) 3a-d, the more stable tautomers of the azadienes 2a-d (Scheme 1). This is a new versatile route to enamines of this type. The diester 3a is a known compound that has previously been prepared from methyl â-halo-R-aminopropionate hydrohalides by reaction with bases;2 compounds 3b-d are previously unknown. Other cross-conjugated bis(enamines) of this type have been produced by thermal rearrangement of vinylaziridines.3 These compounds undergo an interesting photocyclization to 3,4-dihydropyrroles that can be intercepted, as 1,3-dipoles, in cycloaddition reactions with alkenes and alkynes.2b,3,4 Compound 3a is also reported to react as an electrophile with hydrazines5 and with primary amines,6 giving hydrazones and imines of methyl pyruvate as products. In an attempt to cyclize the diester 3a directly to dimethyl pyrrole-2,5-dicarboxylate by using DDQ as an oxidant, a single product was isolated in high yield. Instead of the pyrrole, it proved to be an interesting 1:1 adduct of the diester and DDQ whose structure 4 was established for the compound by X-ray crystallography (Figure 1). The X-ray analysis clearly shows that the C9-C10N1-C2-C3-C4 and C4-C5-C6-C7-C8-C9 rings are fused cis around the common C4-C9 bond and are furthermore linked by the methylenic bridge C10-C11C5. The conformation of the two above-mentioned rings is intermediate between E1 envelope and H2 half-chair, as shown by the ring puckering parameters7 Q ) 0.662(4) A, θ ) 53.8(3)°, φ ) 13.9(4)° [C9-C10-N1-C2-C3C4], Q ) 0.630(4) A, θ ) 53.8(4)°, φ ) 8.2(5)° [C4-C5C6-C7-C8-C9]. The conformation of the bridging ring C4-C5-C11-C10-C9 is very close to T1 (twisted around the C4-C9 bond), as shown by the puckering parameters Q(2) ) 0.566(4) A, φ(2) ) 163.3(4)°. The H1 atom is shared in a bifurcated intramolecular hydrogen bond [N1-H1‚‚‚O1: 2.714(4) A; N1-H1‚‚‚O4: 2.677(5) A, sum of the valence angles around H1 ) 358.2°]. The methoxycarbonyl group attached to the sp2 C2 atom is almost coplanar with the plane defined by the C10-N1-C2 atoms, whereas the other methoxycarbonyl group that is attached to the tetrahedric C10 atom is twisted by -16.9(5)° around the C10-C12 single bond. The H5 atom of the hydroxyl group is also involved in a bifurcated † Departamento de Quimica. ‡ Departamento de Fisica. (1) (a) Gilchrist, T. L.; Rocha Gonsalves, A. M. d’A.; Pinho e Melo, T. M. V. D. Tetrahedron 1994, 50, 13709-13724. (b) Pinho e Melo, T. M. V. D.; Fausto, R.; Rocha Gonsalves, A. M. d’A.; Gilchrist, T. L. J. Org. Chem. 1998, 63, 5350-5355. (2) (a) Mitsuhashi, K. Asahi Garasu Kogyo Gijutsu Shoreikai Kenkyu Hokoku 1973, 23, 355-362; Chem. Abstr. 1975, 82, 86591. (b) Zaima, T.; Matsunaga, Y.; Mitsuhashi, K. J. Heterocycl. Chem. 1983, 20, 1-4. (3) Gelas-Mialhe, Y.; Mabiala, G.; Vessiere, R. J. Org. Chem. 1987, 52, 5395-5400. (4) (a) Zaima, T.; Matsuno, C.; Matsunaga, Y.; Mitsuhashi, K. J. Heterocycl. Chem. 1984, 21, 445-448. (b) Zaima, T.; Matsuno, C.; Matsunaga, Y.; Mitsuhashi, K. Nippon Kagaku Kaishi 1984, 12931298; Chem. Abstr. 1984, 101, 230340. (5) Zaima, T.; Mitsuhashi, K. Nippon Kagaku Kaishi 1979, 901905; Chem. Abstr. 1979, 91, 140303. (6) Zaima, T.; Matsuno, C.; Mitsuhashi, K. Nippon Kagaku Kaishi 1983, 152-156; Chem. Abstr. 1983, 98, 179141. (7) Cremer, D.; Pople, J. A. J. Am. Chem. Soc. 1975, 97, 1354. Figure 1. X-ray structure of compound 4.

Divinylamines (3a - 3d) were prepared by reaction of the corresponding thiazolidines (1a - 1d) with silver carbonate and DBU. The reaction of 3a with DDQ led to the synthesis of an azepine derivative 7.

C11H11NO4, orthorhombic, Pna21 (no. 33), a = 18.370(4) Å, b = 4.870(1) Å, c = 24.616(2) Å, V = 2202.4 Å3, Z = 8, Rgt(F) = 0.082, wRref(F2) = 0.203, T = 293 K.