Thursday 2 April 2015

An efficient and inexpensive device for undergraduate chemistry classes aiming teaching the photolytic synthesis concepts


Quim. Nova 2014, 37(1), 164-167,  2014

Um reator fotoquímico barato e eficiente para experimentos de química

Ramon Kenned Sousa AlmeidaI; Cláudia MartelliI; Gilson Herbert Magalhães DiasI; Julio Cesar Araujo da SilvaII, *
An efficient and inexpensive device for undergraduate chemistry classes aiming teaching the photolytic synthesis concepts. This device presents simplicity, low costs, class-compatible reaction times and good yields. Ramon Kenned Sousa Almeidaa , Cláudia Martellia , Gilson Herbert Magalhães Diasa e Julio Cesar Araujo da Silvab,* a Instituto de Química, Universidade Estadual de Campinas, 13083-970 Campinas – SP, Brasil b Instituto Federal de Ciência e Tecnologia de Santa Catarina, Estrada do Senadinho, s/no , Centro, 88625-000 Urupema – SC, Brasil A CHEAP AND EFFICIENT PHOTOCHEMICAL REACTOR FOR CHEMICAL EXPERIMENTS. In this work, we present an efficient and inexpensive device for undergraduate chemistry classes aimed at teaching and learning the photolytic synthesis concepts. A photochemical reactor was tested for the synthesis of the organometallic compound enneacarbonyldiiron from iron pentacarbonyl in acetic acid, and its formation evidenced by FTIR analysis. Although similar devices have been described in other studies, none of these offered the simplicity, low cost, class-compatible reaction times and good yields afforded by the procedure reported herein. Keywords: photochemistry; reactor; enneacarbonyldiiron.   Displaying image001.png   Displaying image002.png     Displaying image003.png     Displaying image004.png   Displaying image005.png   Displaying image006.png         Instituto de Química, Universidade Estadual de Campinas  
    1. Map of state university of meadows institute of chemistry
  Instituto Federal de Ciência e Tecnologia de Santa Catarina, Estrada do Senadinho
Campus Palhoça-Bilingue. Atualizado por Rafael Batista. O Instituto Federal de Educação, Ciência e Tecnologia de Santa Catarina ...     Aberto o concurso do Instituto Federal de Educação, Ciência e Tecnologia de Santa Catarina (IFSC). A seleção visa prover um total de 145 vagas.   Instituto Federal de Educação, Ciência e Tecnologia - Campus Rio do Sul - Cantagalo

Tuesday 31 March 2015

Simple and effective method for two-step synthesis of 2-(1,3-dithian-2-ylidene)-acetonitrile

Simple and effective method for two-step synthesis of 2-(1,3-dithian-2-ylidene)-acetonitrile (75% overall yield) and molecular modeling calculation of the mechanism by B3LYP and the 6-311++G(2df,2p) basis set.

http://dx.doi.org/10.5935/0100-4042.20140308

Publicado online: dezembro 12, 2014

Método alternativo para a síntese e mecanismo de 2-(1,3-ditiano-2-ilideno)-acetonitrila

Marcelle S. Ferreira; José D. Figueroa-Villar*
Quim. Nova, Vol. 38, No. 2, 233-236, 2015
Artigo http://dx.doi.org/10.5935/0100-4042.20140308
*e-mail: jdfv2009@gmail.com
MÉTODO ALTERNATIVO PARA A SÍNTESE E MECANISMO DE 2-(1,3-DITIANO-2-ILIDENO)-ACETONITRILA
Marcelle S. Ferreira e José D. Figueroa-Villar* Departamento de Química, Instituto Militar de Engenharia, Praça General Tiburcio 80, 22290-270
Rio de Janeiro – RJ, Brasil
Recebido em 18/08/2014; aceito em 15/10/2014; publicado na web em 12/12/2014
ALTERNATIVE METHOD FOR SYNTHESIS AND MECHANISM OF 2-(1,3-DITHIAN-2-YLIDENE)-ACETONITRILE. We report an alternative method for the synthesis of 2-(1,3-dithian-2-ylidene)-acetonitrile using 3-(4-chlorophenyl)-3-oxopropanenitrile and carbon disulfide as starting materials. The methanolysis of the intermediate 3-(4-chlorophenyl)-2-(1,3-dithian-2-ylidene)-3- oxopropanenitrile occurs via three possible intermediates, leading to the formation of the product at a 75% overall yield. Molecular modeling simulation of the reaction pathway using B3LYP 6-311G++(2df,2p) justified the proposed reaction mechanism. Keywords: 2-(1,3-dithian-2-ylidene)-acetonitrile; reaction mechanism; methanolysis; molecular modeling.
3-(4-clorofenil)-2-(1,3-ditiano-2-ilideno)-3-oxopropanonitrila (3): Cristal amarelo. Rendimento: 95%, 2,80 g, pf 158-160 °C, lit.21 159-160 °C;
IV (KBr, cm-1): 2198 (CN), 1612 (C=O), 1585, 1560 (aromático), 678 cm -1 (C-S);
1H RMN (300 MHz, CDCl3) δ 2,38 (m, J 6,9, 2H, CH2); 3,01 (t, J 6,6, 2H, SCH2); 3,17 (t, J 7,2 , 2H, SCH2); 7,43 (d, J 8,5, 2H); 7,83 (d, J 8,5, 2H);
13C RMN (75 MHz, CDCl3) δ 23,9 (CH2), 30,4 (SCH2), 104,2 (CCO), 117,5 (CN), 128,9, 130,5, 135,6, 139,2 (aromático), 185,2 (C=CS), 185,4 (CO).
21.......Rudorf, W. D.; Augustin, M.; Phosphorus Sulfur Relat. Elem. 1981, 9, 329.
...........................................
Síntese da 2-(1,3-ditiano-2-ilideno)-acetonitrila (1) Em um balão de fundo redondo de 100 mL foram adicionados 0,400 g (1,4 mmol) de 3-(4-clorofenil)-2-(1,3-ditiano-2-ilideno)-3- -oxopropanonitrila (2) dissolvidos em 15 mL de THF seco, 0,140 g (20 mmol) de sódio e 15 mL de metanol seco sob atmosfera de nitrogênio. A mistura reacional foi mantida sob agitação à 25 °C por 48 h. Em seguida, a mistura reacional foi dissolvida em 30 mL de água destilada e extraída com acetato de etila (3 x 20 mL). A fase orgânica foi seca em sulfato de sódio anidro, filtrada e concentrada a vácuo para se obter o produto bruto, que foi purificado por cromatografia em coluna (silica gel e hexano:acetato de etila 7:3).
2-(1,3-ditiano-2-ilideno)-acetonitrila (1): Cristal branco. Rendimento: 75%, 165 mg, pf. 60-63 °C, lit1 60-62 °C;
1 H RMN (300 MHz, CDCl3) δ 2,23 (m, J 6,8, 2H, CH2); 3,01 (t, J 7,5, 2H, SCH2); 3,06 (t, J 6,9, 2H, SCH2), 5,39 (s, 1H, CH);
13C RMN (75 MHz, CDCl3) δ 22,9 (CH2), 28,7 (SCH2), 28,8 (SCH2), 90,4 (CHCN), 116,3 (CN), 163,8 (C=CS).
1.........Yin, Y.; Zangh, Q.; Liu, Q.; Liu, Y.; Sun, S.; Synth. Commun. 2007, 37, 703.
 Acetonitrile, 1,3-dithian-2-ylidene-

CAS 113998-04-2

  • C6 H7 N S2
  • Acetonitrile, 2-​(1,​3-​dithian-​2-​ylidene)​-
  • 157.26
Melting Point60-62 °C
1H  NMR  predict
2-(1,3-dithian-2-ylidene)-acetonitrile
BR 1H
BR 1H 1
ACTUAL 1H NMR VALUES
1 H RMN (300 MHz, CDCl3)
δ 2,23 (m, J 6,8, 2H, CH2);
3,01 (t, J 7,5, 2H, SCH2);
3,06 (t, J 6,9, 2H, SCH2),
5,39 (s, 1H, CH);
..........................
13C NMR PREDICT
BR 13C
BR 13C 1
ACTUAL 13C NMR VALUE
13C RMN (75 MHz, CDCl3)
δ 22,9 (CH2),
28,7 (SCH2),
28,8 (SCH2),
90,4 (CHCN),
116,3 (CN),
163,8 (C=CS)
COSY NMR PREDICT
COSY NMR prediction (6)
SYNTHESIS
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2-(1,3-ditiano-2-ilideno)-acetonitrila (1): Cristal branco. Rendimento: 75%, 165 mg, pf. 60-63 °C, lit1 60-62 °C;

1 H RMN (300 MHz, CDCl3) δ 2,23 (m, J 6,8, 2H, CH2); 3,01 (t, J 7,5, 2H, SCH2); 3,06 (t, J 6,9, 2H, SCH2), 5,39 (s, 1H, CH);

13C RMN (75 MHz, CDCl3) δ 22,9 (CH2), 28,7 (SCH2), 28,8 (SCH2), 90,4 (CHCN), 116,3 (CN), 163,8 (C=CS). 

WILL BE UPDATED WATCH OUT.....................
Departamento de Química, Instituto Militar de Engenharia, Praça General Tiburcio
Instituto Militar de Engenharia, Rio de Janeiro. BELOW
Entrada do antigo Instituto de Química da UFRGS, um prédio histórico
Equipe - Os módulos foram fabricados na Unisanta sob a supervisão do professor Luiz Renato Lia, coordenador do Curso de Engenharia Química, ...
Instituto de Florestas da Universidade Federal Rural do Rio de Janeiro
Praça General Tibúrcio
Praça General Tibúrcio com o Morro da Urca ao fundo
P.S. : The views expressed are my personal and in no-way suggest the views of the professional body or the company that I represent.
P.S. : The views expressed are my personal and in no-way suggest the views of the professional body or the company that I represent.
P.S. : The views expressed are my personal and in no-way suggest the views of the professional body or the company that I represent.

Enzymatic resolution of antidepressant drug precursors in an undergraduate laboratory

 
EducaçãoQuim. Nova 2015, 38(2), 285-287

Enzymatic resolution of antidepressant drug precursors in an undergraduate laboratory

Luís M. R. SolanoI; Nuno M. T. LourençoII,*
This paper describes a multi-step chemo-enzymatic synthesis of antidepressant drug precursors.

http://dx.doi.org/10.5935/0100-4042.20140306

Publicado online: novembro 13, 2014
 
Quim. Nova, Vol. 38, No. 2, 285-287, 2015
 
Educação http://dx.doi.org/10.5935/0100-4042.20140306
 
*e-mail: nmtl@tecnico.ulisboa.pt
 
ENZYMATIC RESOLUTION OF ANTIDEPRESSANT DRUG PRECURSORS IN AN UNDERGRADUATE LABORATORY
 
Luís M. R. Solanoa and Nuno M. T. Lourençob,* a Faculdade de Farmácia da Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal b Departamento de Bioengenharia, Instituto de Biotecnologia e Bioengenharia, Instituto Superior Técnico, Av. Rovisco Pais, 1, 1049-001 Lisboa, Portugal
 
Recebido em 07/07/2014; aceito em 17/09/2014; publicado na web em 13/11/2014
The use of biocatalysts in synthetic chemistry is a conventional methodology for preparing enantiomerically enriched compounds. Despite this fact, the number of experiments in chemical teaching laboratories that demonstrate the potential of enzymes in synthetic organic chemistry is limited. We describe a laboratory experiment in which students synthesized a chiral secondary alcohol that can be used in the preparation of antidepressant drugs. This experiment was conducted by individual students as part of a Drug Synthesis course held at the Pharmacy Faculty, Lisbon University. This laboratory experiment requires six laboratory periods, each lasting four hours. During the first four laboratory periods, students synthesized and characterized a racemic ester using nuclear magnetic resonance spectroscopy and gas chromatography. During the last two laboratory periods, they performed enzymatic hydrolysis resolution of the racemic ester using Candida antarctica lipase B to yield enantiomerically enriched secondary alcohol. Students successfully prepared the racemic ester with a 70%-81% overall yield in three steps. The enzymatic hydrolysis afforded (R)- secondary alcohol with good enantioselectivity (90%–95%) and reasonable yields (10%–19%). In these experiments, students were exposed to theoretical and practical concepts of aromatic acylation, ketone reduction, esterification, and enzymatic hydrolysis. Keywords: sec-alcohols; esters; lípase; enantiomers; resolution.
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Sunday 22 March 2015

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Thursday 12 March 2015

Odorless and Efficient Thioacetalization Reaction of Oximes





Chemical Journal of Chinese Universities  2012, Vol. 33 Issue (09): 1969-1972
DOI: 10.3969/j.issn.0251-0790.2012.09.016 http://www.cjcu.jlu.edu.cn/EN/abstract/abstract24471.shtml# http://www.cjcu.jlu.edu.cn/EN/volumn/next.shtml  
Odorless and Efficient Thioacetalization Reaction of Oximes    
YU Hai-Feng1, LIAO Pei-Qiu2
1. School of Chemistry and Life Science, Anshan Normal University, Anshan 114007, China;
2. Department of Chemistry, Northeast Normal University, Changchun 130024, China
Download: PDF (581 KB) Export: BibTeX | EndNote (RIS)      Supporting Info
Abstract  Thioacetals are important compounds because they can be considered as both useful protecting groups of carbonyl compounds in the synthesis of multi-functional complex molecules and acyl carbanion equi-valents in C—C bond forming reactions. Since many reactions have been developed to prepare oximes from non carbonyl compounds, to lead to a novel and efficient method for thioacetal preparation, transthioacetalization of oximes has received more and more attention. Unfortunately, the transformation usually suffers from the use of harmful, odorous thiols which can lead to serious safety and environment problems. From the green chemistry point of view, an efficient and odorless transthioacetalization of oximes involving an environment friendly reagent is of great importance and necessity. In this work, using odorless and stable α-oxo ketene dithioacetals 1 as thiol equivalents, the thioacetalization reaction of oximes 2 were studied. In the reaction system of MeCOCl-EtOH(95%) or 4-dodecylbenzenesulfonic acid(DBSA)-H2O, the thioacetalization reaction were carried out in reflux temperature. It is noteworthy that the odor of thiols can not be perceived during either the reaction or workup.
 Odorless and Efficient Thioacetalization Reaction of Oximes[J].
Chemical Journal of Chinese Universities, 2012, 33(09): 1969-1972.
URL:
http://www.cjcu.jlu.edu.cn/EN/10.3969/j.issn.0251-0790.2012.09.016     OR
  http://www.cjcu.jlu.edu.cn/EN/Y2012/V33/I09/1969
  Odorless and Efficient Thioacetalization Reaction of Oximes.pdf (1)


  Odorless and Efficient Thioacetalization Reaction of Oximes.pdf (2)


Anshan Normal University, Anshan 114007, China















Department of Chemistry, Northeast Normal University, Changchun 130024, China - See more at: http://organicsynthesisinternational.blogspot.in/#sthash.dl5jq4SB.dpuf