Ethyl 4-(2-fur­yl)-2-oxochroman-3-carboxyl­ate

The title compound, C16H14O5, was prepared from the reaction of 3-carbethoxy­coumarin with furan in the presence of AlCl3 as catalyst. In the crystal, inter­molecular C—H⋯O hydrogen-bonding inter­actions between four mol­ecules lead to a tetra­mer in the unit cell. The furan ring is anti­periplanar [C—C—C—O = 167.9 (13)°] and the ethoxy­carbonyl group is (−)anti­clinal [C—C—C—O = −128.6 (14)°] to the lactone ring

Pharmaceutical cognitive enhancement in Greek university students: differences between users and non-users in social cognitive variables, burnout and engagement

Pharmaceutical cognitive enhancement (PCE) represents the non-medical use of prescribed medication for the improvement of cognitive functioning and academic performance. Although there are some studies about PCE prevalence, it is less clear how users and non-users of PCE substances differ with respect to their positive and negative student experiences (e.g., academic burnout, engagement with studies) and in social cognitive variables that relate to decision-making and self-regulation of PCE use. The present study assessed whether students with different experiences of PCE substance use displayed differences in academic burnout, study engagement and social cognitive variables relevant to PCE use. Three hundred and forty seven University students (M age = 22.15, SD = 1.69; 54% females) completed a battery of anonymous questionnaires on academic burnout, engagement with studies, social cognitive variables relevant to PCE use, and self-reported use of PCE substances and non-prescribed nutritional supplements. Three user groups emerged, namely, non-users (51.9%, n = 180), single users of non-prescribed dietary supplements (25.4%, n = 88), and dual users of both non-prescribed dietary supplements and PCE (22.8%, n = 79). Multivariate analysis of variance indicated significant differences among the three user groups in intentions, attitudes, social norms, and anticipated regret towards PCE use. No significant differences were observed with respect to academic burnout and work engagement. The findings show that University students may engage in PCE use independently of their student experiences. Rather, a chemically-assisted performance enhancement mindset seems to differentiate users from non-users of PCE substances

Sinteza kumarinskih heterocikličkih derivata s antioksidativnim djelovanjem i in vitro citotoksično djelovanje na tumorske stanice

The aim of the present work was to synthesise coumarinyl heterocycles and to elucidate the potential role of these compounds as antioxidants and cytotoxic agents against Dalton\u27s lymphoma ascites tumour cells (DLA) and Ehrlich ascites carcinoma cells (EAC). The synthesis of coumarin derivatives containing pyrazole, pyrazolone, thiazolidin-4-one, 5-carboxymethyl-4-thiazolidinone and 3-acetyl-1,3,4-oxadiazole ring is reported. 4-Methylcoumarinyl-7-oxyacetic acid hydrazide (1) reacted with arylazopropanes or hydrazono-3-oxobutyrate derivatives to form pyrazole (3a-c) and pyrazolone derivatives (5a-c). Heterocyclisation of Schiffs bases of 1 with thioglycolic acid, thiomalic acid or acetic anhydride afforded novel heterocyclic derivatives 4-thiazolidinones (7a-c), 5-carboxymethyl-4-thiazolidinones (8a-c) and oxadiazoles (9a-c), respectively. Some of the compounds showed promising results in in vitro antioxidant activity and cytotoxic activity against DLA cells and EAC cells.Cilj rada bio je sintetizirati kumarinske heterocikličke derivate i razjasniti njihovu potencijalnu ulogu kao antioksidativnih i citotoksičnih agenasa na tumorske stanice Daltonovog limfoma (DLA) i Ehrlichove tumorske stanice (EAC). U radu je opisana sinteza kumarinskih derivata s pirazolskim, pirazolonskim, tiazolidin-4-onskim, 5-karboksimetil-4-tiazolidinonskim i 3-acetil-1,3,4-oksadiazolskim prstenom. Hidrazid 4-metilkumarinil-7-oksioctene kiseline (1) dao je u reakciji s derivatima arilazopropana ili hidrazono-3-oksobutirata derivate pirazola (3a-c) i pirazolona (5a-c). Heterociklizacijom Schiffovih baza 1 s tioglikolnom kiselinom, tiojabučnom kiselinom ili anhidridom octene kiseline nastali su heterociklički derivati 4-tiazolidinoni (7a-c), 5-karboksimetil-4-tiazolidinoni (8a-c) i oksadiazoli (9a-c). Neki od spojeva pokazali su obećavajuće rezultate u in vitro testovima za antioksidativno i citostatsko djelovanje na DLA i EAC stanicama pokazali

On the form of Lie symmetries of systems with three pdes: The examples of two variable coefficient Hirota Satsuma systems

We consider a general class of systems of three partial differential equations and we provide restrictions on the form of Lie symmetry operators admitted by such systems. When these restrictions are known in advance, the symmetry analysis becomes simpler. Special cases of this class are two generalizations of Hirota–Satsuma systems with variable coefficients. We derive the equivalence groups for these two systems. With the aid of the equivalence groups and the restricted form of the Lie symmetry operators, we present an enhanced Lie group classification for the two Hirota–Satsuma systems. For each class a specific system is single out which has the property to be mapped into a constant coefficient system