Online ISSN: 2515-8260

Keywords : catalyst


DEVELOPMENT OF SELECTIVE SENSORS FOR DETERMINATION OF ETHYL ALCOHOL VAPORS

Ergashboy Abdurakhmanov; Zulfiya Begmuradovna Murodova; Farrukh Fakhriddinovich Kholmurzaev; Bakhtiyor Bakhodir ugli Akhmedov

European Journal of Molecular & Clinical Medicine, 2020, Volume 7, Issue 9, Pages 2769-2779

The paper establishes the regularities of the oxidation of combustible substances in the presence of catalytic systems of different nature and on their basis the catalysts for measuring and compensation sensitive elements of a thermocatalytic ethanol vapor sensor are selected. The possibility of creating highly sensitive and selective sensors with the use of measuring and compensating thermosensitive elements of the sensor containing catalysts of different activity to the components of complex gas-air mixtures has been experimentally confirmed.The main metrological characteristics and operational parameters of the developed selective thermocatalytic ethanol sensors are estimated. The developed utensils allow the determination of ethyl alcohol vapors in wide ranges of its concentrations and have the best metrological characteristics and operational parameters.

Bifunctional Thiourea–Amine based Organocatalyst excelling in Multi Component Reactions

Monika Verma; Renu Sharma; Ruchi Bharti

European Journal of Molecular & Clinical Medicine, 2020, Volume 7, Issue 7, Pages 4529-4542

Recently, exclusive feature of small organic molecules i.e., organocatalysts like low cost,
environment benign, nonmetallic, solubility, stability in normal conditions, easy
availability has made it, a very attractive catalyst to unified diverse fields in synthetic
organic chemistry. Organocatalysts specifically based on thiourea-amine based attained a
great attention among research propagators. These catalysts are capable of activating an
electrophile through hydrogen bond formation and at the same time, activate nucleophile
by involving amine group. In spite of great advantage of this catalyst, a very little work has
been done with it in multicomponent reactions (MCRs). To explore the applications of
these catalysts in MCRs we focused on the utilization of these dual functionalility
containing moieties in MCRs.

THE EFFECT OF PYRIDINE AND TRIETHYLAMINE (TEA) CATALYSTS IN THE SYNTHESIS OF THE 4- BENZOYLOXY-3-METHOXYCINNAMIC ACID THROUGH MICROWAVE IRRADIATION METHOD

Indi Mumtaza; Juni Ekowati; Kholis Amalia Nofianti

European Journal of Molecular & Clinical Medicine, 2020, Volume 7, Issue 1, Pages 3884-3894

In this study, 4-hydroxy-3-methoxycinnamic acid and benzoyl chloride was reacted through the nucleophilic acyl substitution mechanism by using pyridine and triethylamine (TEA) as catalysts.This study aims to discern whether the 4-benzoyloxy-3-methoxycinnamic acid compound can be synthesized from 4-hydroxy-3-methoxycinnamic acid and benzoyl chloride by using pyridine and triethylamine (TEA) catalysts through microwave irradiation method. Also, this study is to discover which catalyst gives the most significant percentage of results in synthesizing 4-benzoyloxy-3-methoxycinnamic acid.This study was an experimental study, which synthesized 4-benzoyloxy-3-methoxycinnamic acid through microwave irradiation method at 180, 360, and 540 watts of power to determine the selected conditions of synthesis with pyridine catalyst.The results indicated that triethylamine (TEA) catalyst significantly gave a higher percentage of results (71.8%) than pyridine catalyst did (65.3%). The results were due to the inductive effect of ethyl on TEA and the effect of pyridine resonance associated with its basicity. The FT-IR spectrophotometry and the 1HNMR spectrometry profile confirmed that the product of both conditions was 4-benzoyloxy3-methoxycinnamic acid. The purity of the outcome of both reaction conditions was then determined by the melting point test and thin-layer chromatography (TLC), which revealed that the product was pure.The synthesis of 4-hydroxy-3-methoxycinnamic acid with benzoyl chloride pyridine catalyst can be carried out with microwave irradiation. Meanwhile, the synthesis with benzoyl chloride triethylamine (TEA) catalyst with microwave irradiation can only be performed at 540 watts of power. The catalyst with the more significant percentage of results, thus, is TEA catalyst with a percentage of 71.8%±1.3.