Antimony lone electronic pair as a stereoelectronic barrier to stibatrane

To examine the effect of 5s2 lone electron pair of antimony atom on the reaction of antimony trifluoride and triethanolamine in the presence of sodium methylate, the crystal structure of the reaction product -2-fluoro-6-(2-hydroxyethyl)-1,3-dioxa-6-aza-2-stibacy-cylooctane (1-fluoro-2-hydrostibatrane) FSb (OCH2CH2)2NCH2CH2OH) was confirmed. In the compound structure, the hydrogen atom of the 2-hydtoxyethyl group of each molecule forms an intermolecular hydrogen bond with the oxygen atom of one of the five-membered SbOCH2CH2N half-cycles in a neighbouring molecule. A geometry of both five-member N-C-C-O-Sb heterocycles, end-capped by transannular N→Sb bond in the 1-fluoro-2-hydrostibatrane molecule, is almost identical. C-O, C-C, N-C interatomic distances and valence angles in two endocyclic units (NCCOSb) are comparable to those observed in RSi(OCH2CH2)3N silatranes. A coordination polyhedron of the Sb atom can be represented as a transition from a bisphenoid to Sb(O3)N trigonal pyramid, with a nitrogen atom at the apex and three oxygen atoms in the base. The N→Sb transannular coordinate bond length is 2.402(4) Å, which is 0.40 Å greater than the Sb-N covalent bond standard length. The Sb-F bond (1.997(4) Å) is 0.12 Å longer than that in the SbF3 molecule, and insignificantly shorter than that of the Sb-Fax (2.028(3) Å) in the SbF3Gly crystalline complex. The fluorine atom substantially strays from the N→Sb axis to the direction of O(1) and O(2) atoms. The oxygen atom of the 2-hydroxyethyl group lies at a distance of 2.899(3) A from that of Sb, intermediate between the valence bond length and the sum of the Van der Waals radii of these atoms. Combined with the F atom position, one can assume the 1-fluoro-2-hydrostibatrane crystal structure as a “frozen” state of the SNi(Sb) type nucleophilic attack of the oxygen atom, uncompleted because of its repulsion by the 5s2 lone electronic pair of antimony atom.

Transeterification of a Mixture of Vegetable Fats with the Addition of Phytosterols

Pure phytosterols that are sparingly soluble in oils were subjected to a transesterification reaction using the catalyst sodium methylate in a mixture of palm stearin: palm oil: sunflower oil. As a comparison, transesterification was performed under the same conditions without the addition of phytosterols. To determine the qualitative composition of the mixture transesterified with phytosterols, analyzes were performed on the fatty acid composition, sterol composition, and melting point. The resulting product differed from the control by the presence of a characteristic odor, sterol composition, melting point.

Kinetic Study of the Herrmann–Beller Palladacycle-Catalyzed Suzuki–Miyaura Coupling of 4-Iodoacetophenone and Phenylboronic Acid

This article presents an experimental kinetic study of the Suzuki–Miyaura reaction of 4-iodoacetophenone with phenylboronic acid catalyzed by the Herrmann–Beller palladacycle. This catalyst, together with the solvent (ethanol) and the base (sodium methylate), were chosen to ensure catalyst stability and reactants solubility all along the reaction. Based on the study of initial reaction rates, a quasi-first-order was found for 4-iodoacetophenone with a first-order dependence on the initial concentration of palladium. A zero-order was found for the base and the phenylboronic acid. The oxidative addition step of the mechanism was thus considered as the rate determining step. A global rate law was derived and validated quantitatively. A global activation energy, with an average value of ca. 63 kJ/mol was determined.

MON-129 Analysis of Omega3 PUFAs Status Among the Female and Male Population of the Moscow Region

INTRODUCTION: All humans have levels of EPA+DHA that if methodologically correctly assessed in erythrocytes, are optimal more than 8%. Omega-3 polyunsaturated fatty acids (PUFAs), namely eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are permanent subjects of interest not only in relation to the protection of cardiovascular health and the prevention of the incidence of both ventricular and atrial arrhythmias, but also many serious health issues that can be prevented by optimal levels. OBJECTIVE: The aim of this study was to assess in a retrospective study the omega-3 PUFAs status at Moscow region according age and sex. SUBJECTS AND METHODS: In this retrospective study, the records of 1349 patients who presented with various complaints in the period from 2013 to 2017 aged 1 to 91 were examined. Fatty acids within the red blood cell membranes were analyzed as methyl ethers after trans-esterification with sodium methylate using GC-MS followed by omega-3 index calculation. RESULTS: Deficiency of omega-3 PUFAs was found in 68.5% of patients. The most severe deficiency was noted in children and adolescents aged 0 to 17 years (in girls to a greater extent). In age groups of 18–44 and 45–59 years, the prevalence of severe (<4%) and moderate (4–8%) deficiency was comparable in males and females: among 18–44-year-old men severe deficiency was noted in 5.6%, moderate – in 29.4%, at the age of 45–59 years – in 7 and 23%, respectively; among women – 6.4, 24.4, 8.4 and 20%, respectively. In the age group of 60-74 years, prevalence of severe deficiency was significantly higher in men, who had severe deficiency in 9.2% of cases, whereas in women of the same age it was found only in 4.8% of cases, the prevalence of moderate deficiency is 23 and 23.8%, respectively. CONCLUSIONS: Such high prevalence of severe omega-3 PUFA deficiency in girls under 17 is likely due to girls’ and their parents’ concerns about weight, diet and veganism, and requires the inclusion of omega-3 index analysis in adolescent girls’ screening. Thus, during the most important period – the period of puberty – 25% of girls have metabolic and hypoxic disorders due to deficiency of omega-3 PUFA and are at risk of not only diseases associated with metabolic disorders, but also reproductive disorders (infertility, miscarriage, fetal malformations). The obtained data is indicative of the necessity to choose dosages of omega-3 PUFAs, considering not only the patients age, but also their gender.

BIODIESEL PRODUCTION FROM MICROWAVE IRRADIATED REACTOR USING HOMOGENEOUS AND HETEROGENEOUS CATALYSIS

Biodiesel was successful produced in a microwave irradiation reactor using homogeneous and heterogeneous catalysis. The biodiesel was production by the trasesterification reaction of soybean oil using metanol. Sodium methylate (30% solution in metanol) was used for the homogeneous catalyst and the heterogeneous catalyst was developed using wasted eggshells. The eggshells were calcined and tested pure and doped with potassium hydroxide in 10, 30 and 50% of weight. The power and temperature of the microwave were kept constant in every reaction being 800W and 200º Celsius, respectively. The reaction time was significantly reduced using microwave compared to the conventional process. In only one minute of reaction, the methyl ester (FAME) conversion obtained was 98.9% with the homogeneous catalyst and within 15 minutes, the heterogeneous catalysis accomplished 100%. For heterogeneous catalyst, the best results were acquired when the doped catalyst contained 50% of KOH. The results indicated that the eggshells treated with KOH has a great potential to be used for microwave-assisted transesterification reactions of oils with mild operations conditions: molar ratio oil/alcochol 1:6 and just 5% of catalyst. In addition, the heterogenous catalyst was recovered and reused in other reactions with a relatively satisfying results. The physico-chemical properties of the catalysts were characterized by X-ray diffraction and thermogravimectric analysis.

Synthesis and Growth Stimulant Properties of 2-Acetyl-3,7-dimethyl-5H-thiazolo[3,2-a]pyrimidin-5-one Derivatives

A convenient, accessible, and high yield method for preparing of 6-methyl-2-thioxo-2,3-dihydropyrimidin-4(1H)-one (1) by treatment of acetoacetic acid ethyl ester with thiourea in sodium methylate was developed. The alkylation of the latter with 3-chloro-pentane-2,4-dione and further regioselective cyclization of intermediate compound (2) in high yield afforded 2-acetyl-3,7-dimethyl-5H-thiazolo[3,2-a]pyrimidin-5-one (3). The halogenation and some transformations of synthesized thiazolo[3,2-a]pyrimidine (3) due to its ketone group were carried out to obtain the corresponding carboxamide, carbothioamide, sulfonohydrazide, and oxime and its alkylated derivatives (5). At preliminary biological studies the synthesized compounds have shown growth stimulant properties. The activity of four of them was higher than 70%, compared with heteroauxin.