Ethyl 4, 6-dichloro-1H-indole-2-carboxylate

organic chemistry, spectroscopy, SYNTHESIS Comments Off

Aug 282018

Ethyl 4, 6-dichloro-1H-indole-2-carboxylate

ethyl 4,6-dichloro-1H-indole-2-carboxylate (1a) (2.70 kg, 99.5%).

Mp 187–188 °C; HRMS (ESI) m/z [M – H]⁻ calcd for C₁₁H₈NO₂Cl₂ 255.9927, found 255.9930;

¹H NMR (400 MHz, DMSO-d₆) δ 12.41 (s, 1H), 7.44 (s, 1H), 7.27 (s, 1H), 7.10 (s, 1H), 4.43–4.30 (q, 2H), 1.34 (d, 3H);

¹³C NMR (151 MHz, CDCl₃) δ 161.69, 137.08, 131.00, 128.45, 128.37, 125.31, 121.26, 110.52, 107.07, 61.56, 14.32;

IR (cm^–1) 3314.3, 2987.6, 1700.2, 1615.8, 1566.2, 1523.7, 1487.2, 1323.3, 1247.2, 1072.4, 840.1, 770.2.

Org. Process Res. Dev., Article ASAP

DOI: 10.1021/acs.oprd.8b00144

https://pubs.acs.org/doi/10.1021/acs.oprd.8b00144

https://pubs.acs.org/doi/suppl/10.1021/acs.oprd.8b00144/suppl_file/op8b00144_si_001.pdf

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tert-butyl (N-[3-[(3S,4R)-3-amino-4-fluoro-4-(hydroxymethyl)tetrahydrofuran-3-yl]-4-fluorophenyl]acetamide)

ANTHONY CRASTO, spectroscopy, SYNTHESIS Comments Off

Apr 272018

tert-butyl (N-[3-[(3S,4R)-3-amino-4-fluoro-4-(hydroxymethyl)tetrahydrofuran-3-yl]-4-fluorophenyl]acetamide)

1H-NMR (500 MHz, DMSO-d6): 1.31 (s, 9H), 2.02 (s, 3H), 3.21 (m, 1H), 3.88 (m, 1H), 3.94 (m, 1H), 4.03 (m, 1H), 4.13 (m, 1H), 4.74 (m, 1H), 5.07 (m, 1H), 7.08 (m, 1H), 7.43 (bs, 1H), 7.63 (m, 1H), 7.67 (m, 1H), 10.03 (s, 1H) .

13C-NMR (125 MHz, DMSO-d6): 24.3, 28.5, 60.8, 65.1, 72.6, 78.1, 78.9, 105.8, 116.4, 119.7, 120.8, 127.2, 136.2, 155.2, 156.4, 168.7.

19F-NMR (470.6 MHz, DMSO-d6): -164.77, -117.26.

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Org. Process Res. Dev., Article ASAP

DOI: 10.1021/acs.oprd.8b00069

Avibactam NMR

spectroscopy, Uncategorized Comments Off

Feb 232018

Avibactam, sodium (2S,5R)-2-carbamoyl-7-oxo-1,6-diazabicyclo[3.2.1]octan-6-yl sulfonate,

Avibactam Sodium Salt (1)

white crystalline solid 1 (395.0 g, 96.2%), mp 259.1–262.4 °C (decomposition);

[α]_D²⁰ = −46.40 (c = 0.79, MeOH/H₂O = 1/1);

1H NMR (500 MHz, D₂O) δ 4.15 (dd, J = 5.8, 2.8 Hz, 1H), 4.01 (d, J = 7.5 Hz, 1H), 3.28 (d, J = 12.2 Hz, 1H), 3.06 (d, J = 12.2 Hz, 1H), 2.23–2.09 (m, 1H), 2.06–1.96 (m, 1H), 1.94–1.82 (m, 1H), 1.81–1.69 (m, 1H).

¹³C NMR (126 MHz, D₂O) δ 174.72 (s), 169.53 (s), 60.43 (s), 59.93 (s), 47.33 (s), 20.03 (s), 18.31 (s). IR (cm^–1): 3459, 1749, 1675, 1361, 1270, 1013, 857, 768. MS (ESI) m/z: 279.0 [M + H]⁺.

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Unconventional Method for the Synthesis of 3-Carboxyethyl-4-formyl(hydroxy)-5-arylpyrazoles

spectroscopy, SYNTHESIS, Uncategorized Comments Off

Feb 082018

Unconventional Method for Synthesis of 3-Carboxyethyl-4-formyl(hydroxy)-5-aryl-N-arylpyrazoles

Michael J. V. da Silva^†, Julia Poletto^†, Andrey P. Jacomini^†, Karlos E. Pianoski^†, Davana S. Gonçalves^†, Gessica M. Ribeiro^†, Samara M. de S. Melo^†, Davi F. Back^‡, Sidnei Moura^§, and Fernanda A. Rosa^*^†

^† Departamento de Química, Universidade Estadual de Maringá (UEM), 87030-900 Maringá, PR, Brazil

^‡ Departamento de Química, Universidade Federal de Santa Maria (UFSM), 97110-970 Santa Maria, RS, Brazil

^§ Instituto de Biotecnologia, Universidade de Caxias do Sul (UCS), 295070-560 Caxias do Sul, RS, Brazil

J. Org. Chem., 2017, 82 (23), pp 12590–12602

DOI: 10.1021/acs.joc.7b02361

Publication Date (Web): November 2, 2017

*E-mail: farosa@uem.br

Cite this:J. Org. Chem. 82, 23, 12590-12602

Abstract

An alternative highly regioselective synthetic method for the preparation of 3,5-disubstituted 4-formyl-N-arylpyrazoles in a one-pot procedure is reported. The methodology developed was based on the regiochemical control of the cyclocondensation reaction of β-enamino diketones with arylhydrazines.

Structural modifications in the β-enamino diketone system allied to the Lewis acid carbonyl activator BF₃ were strategically employed for this control. Also a one-pot method for the preparation of 3,5-disubstituted 4-hydroxymethyl-N-arylpyrazole derivatives from the β-enamino diketone and arylhydrazine substrates is described.

J. Org. Chem. 2017, 82, 12590

4-Formyl-N-arylpyrazole substrates occupy a prominent position in the field of organic synthesis since they are key intermediates in obtaining a wide range of biologically active compounds. Because of the synthetic versatility of the 4-formyl-N-arylpyrazole skeleton, their synthesis has been extensively explored. In an extension of their previously published research,

Rosa and co-workers at Universidade Estadual de Maringá described a one-pot synthetic method that regioselectively produced 3,5-disubstituted-4-formyl-N-arylpyrazoles . The β-enamino diketone starting materials were readily synthesized via published procedures. High regioselectivity was secured via the use of BF₃·OEt₂ as the carbonyl activator and a bulky amine as the enamine component. Acetonitrile proved to be the most suitable solvent for the reaction.

After an aqueous workup, the desired pyrazoles were obtained in excellent yields. A variety of functional groups were tolerated on the two aryl substituents. This operationally simple procedure afforded the 4-formyl-N-arylpyrazoles in high yields, regioselectively. Furthermore, the formyl group could be reduced in situ with sodium borohydride to generate the corresponding 4-hydroxymethyl-N-arylpyrazoles.

3-(Ethoxycarbonyl)-4-formyl-5-(4-nitrophenyl)-1-phenyl-1H-pyrazole (3a)

Light yellow solid; yield: 0.150 g (82%); mp 147.0–149.2 °C;

¹H NMR (300.06 MHz, CDCl₃) δ (ppm) 1.47 (t, 3H, J = 7.1 Hz, O–CH₂–CH₃), 4.54 (q, 2H, J = 7.1 Hz, O–CH₂-CH₃), 7.19–7.25 (m, 2H, Ph), 7.32–7.43 (m, 3H, Ph), 7.48 (d, 2H, J = 8.9 Hz, 4-NO₂C₆H₄), 8.19 (d, 2H, J = 8.9 Hz, 4-NO₂C₆H₄), 10.57 (s, 1H, CHO);

¹³C NMR (75.46 MHz, CDCl₃) δ (ppm) 14.4 (O–CH₂–CH₃), 62.3 (O-CH₂–CH₃), 122.0 (C4), 123.5 (4-NO₂C₆H₄), 125.9 (Ph), 129.5 (Ph), 129.6 (Ph), 131.8 (4-NO₂C₆H₄), 134.1 (4-NO₂C₆H₄), 137.8 (Ph), 143.5 (C5), 145.0 (C3), 148.4 (4-NO₂C₆H₄), 161.5 (COOEt), 186.6 (CHO);

HRMS (ESI+): calcd for C₁₉H₁₆N₃O₅⁺, [M+H]⁺: 366.1084, found 366.1101.

//////////////https://pubs.acs.org/doi/abs/10.1021/acs.joc.7b02361

A sustainable procedure toward alkyl arylacetates: palladium-catalysed direct carbonylation of benzyl alcohols in organic carbonates

spectroscopy, SYNTHESIS, Uncategorized Comments Off

Feb 082018

A sustainable procedure toward alkyl arylacetates: palladium-catalysed direct carbonylation of benzyl alcohols in organic carbonates

Green Chem., 2018, Advance Article
DOI: 10.1039/C7GC03619A, Communication

Yahui Li, Zechao Wang, Xiao-Feng Wu
A sustainable procedure for the synthesis of various alkyl arylacetates from benzyl alcohols has been developed

A sustainable procedure toward alkyl arylacetates: palladium-catalysed direct carbonylation of benzyl alcohols in organic carbonates

Yahui Li,^a Zechao Wang^a and Xiao-Feng Wu*^a^b

Author affiliations

* Corresponding authors

^a Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein-Strasse 29a, 18059 Rostock, Germany

^b Department of Chemistry, Zhejiang Sci-Tech University, Xiasha Campus, Hangzhou 310018, People’s Republic of China
E-mail: Xiao-Feng.Wu@catalysis.de

Abstract

A sustainable procedure for the synthesis of various alkyl arylacetates from benzyl alcohols has been developed. With palladium as the catalyst and organic carbonates as the green solvent and in situ activator, benzyl alcohols were carbonylated in an efficient manner without any halogen additives.

Ethyl 2-phenylacetate

1H NMR (300 MHz, Chloroform-d) δ 7.32 – 7.08 (m, 5H), 4.08 (q, J = 7.1 Hz, 2H), 3.54 (s, 2H), 1.18 (t, J = 7.1 Hz, 3H).

13C NMR (75 MHz, CDCl3) δ 171.61, 134.17, 129.24, 128.54, 127.03, 60.85, 41.45, 14.18.

//////http://pubs.rsc.org/en/Content/ArticleLanding/2018/GC/C7GC03619A?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2FGC+%28RSC+-+Green+Chem.+latest+articles%29#!divAbstract

Stable and reusable nanoscale Fe2O3-catalyzed aerobic oxidation process for the selective synthesis of nitriles and primary amides

organic chemistry, spectroscopy, SYNTHESIS Comments Off

Dec 292017

Stable and reusable nanoscale Fe2O3-catalyzed aerobic oxidation process for the selective synthesis of nitriles and primary amides

Green Chem., 2018, Advance Article
DOI: 10.1039/C7GC02627G, Paper

Kathiravan Murugesan, Thirusangumurugan Senthamarai, Manzar Sohail, Muhammad Sharif, Narayana V. Kalevaru, Rajenahally V. Jagadeesh
Nanoscale Fe₂O₃-catalyzed environmentally benign synthesis of nitriles and amides has been performed from easily accessible aldehydes and ammonia using O₂.

http://pubs.rsc.org/en/Content/ArticleLanding/2018/GC/C7GC02627G?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2FGC+%28RSC+-+Green+Chem.+latest+articles%29#!divAbstract

Stable and reusable nanoscale Fe₂O₃-catalyzed aerobic oxidation process for the selective synthesis of nitriles and primary amides

Kathiravan Murugesan,^a Thirusangumurugan Senthamarai,^a Manzar Sohail,^b Muhammad Sharif,^b Narayana V. Kalevaru^a and Rajenahally V. Jagadeesh*^a

Author affiliations

* Corresponding authors

^a Leibniz-Institut für Katalyse e. V. an der Universität Rostock, Albert-Einstein-Str. 29a, 18059 Rostock, Germany
E-mail:Jagadeesh.Rajenahally@catalysis.de

^b The Center of Research Excellence in Nanotechnology (CENT) and Department of Chemistry, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia

Abstract

The sustainable introduction of nitrogen moieties in the form of nitrile or amide groups in functionalized molecules is of fundamental interest because nitrogen-containing motifs are found in a large number of life science molecules, natural products and materials. Hence, the synthesis and functionalization of nitriles and amides from easily available starting materials using cost-effective catalysts and green reagents is highly desired. In this regard, herein we report the nanoscale iron oxide-catalyzed environmentally benign synthesis of nitriles and primary amides from aldehydes and aqueous ammonia in the presence of 1 bar O₂ or air. Under mild reaction conditions, this iron-catalyzed aerobic oxidation process proceeds to synthesise functionalized and structurally diverse aromatic, aliphatic and heterocyclic nitriles. Additionally, applying this iron-based protocol, primary amides have also been prepared in a water medium.

1H NMR (300 MHz, Chloroform-d) δ 7.17 – 6.96 (m, 2H), 6.93 – 6.70 (m, 1H), 4.33 – 4.11 (m, 4H). 13C NMR (75 MHz, Chloroform-d) δ 147.75 , 143.80 , 125.87 , 121.21 , 118.91 , 118.25 , 104.38 , 64.59 , 64.12 . Off white solid

cas 19102-07-9

1,4-Benzodioxan-6-carbonitrile (8CI)
2,3-Dihydro-1,4-benzodioxin-6-carbonitrile
1-(2,3-Dihydrobenzo[b][1,4]dioxin-6-yl)nitrile

Melting Point, °C
105 – 106 Tetrahedron, 2015, vol. 71, 29, p. 4883 – 4887

Melting Point, °C

105 – 106

Tetrahedron, 2015, vol. 71, 29, p. 4883 – 4887

NMR PREDICTS

1H NMR

13C NMR PREDICT

More…………….

Journal of the American Chemical Society, 2001, vol. 123, 49, p. 12202 – 12206

More………….

RSC Advances, 2013, vol. 3, 44, p. 22389 – 22396

http://www.rsc.org/suppdata/ra/c3/c3ra44386h/c3ra44386h.pdf

MORE……..

Organic Letters, 2017, vol. 19, 12, p. 3095 – 3098

http://pubs.acs.org/doi/suppl/10.1021/acs.orglett.7b01199/suppl_file/ol7b01199_si_001.pdf

2,3-Dihydrobenzo[b][1,4]dioxine-6-carbonitrile (Scheme 1, 2n) According to the general procedure A, the reaction of 1n (0.20 mmol), zinc cyanide (2.0 equiv), PCyPh2 (0.20 equiv) and Pd(OAc)2 (0.05 equiv) in dioxane (0.25 M) for 16 h at 150 °C, afforded after work-up and chromatography the title compound in 75% yield (24.2 mg). White solid. 1H NMR (500 MHz, CDCl3) δ 7.17-7.11 (m, 2H), 6.91 (d, J = 8.1 Hz, 1H), 4.32-4.31 (m, 2H), 4.30- 4.26 (m, 2H). 13C NMR (125 MHz, CDCl3) δ 147.84, 143.91, 126.04, 121.37, 119.01, 118.37, 104.62, 64.71, 64.24.

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Synthesis of highly functional carbamates through ring-opening of cyclic carbonates with unprotected α-amino acids in water

organic chemistry, spectroscopy, SYNTHESIS Comments Off

Dec 202017

Synthesis of highly functional carbamates through ring-opening of cyclic carbonates with unprotected [small alpha]-amino acids in water

Green Chem., 2018, Advance Article
DOI: 10.1039/C7GC02862H, Paper

Peter Olsen, Michael Oschmann, Eric V. Johnston, Bjorn Akermark
Ring opening of cyclic carbonates with unprotected amino acids in water – a route to highly functional carbamates.

Synthesis of highly functional carbamates through ring-opening of cyclic carbonates with unprotected α-amino acids in water

Peter Olsén,*^a Michael Oschmann,^a Eric V. Johnston*^a and Björn Åkermark*^a

Author affiliations

*Corresponding authors

^aDepartment of Organic Chemistry, Arrhenius Laboratory, Stockholm University, SE 106 91, Stockholm, Sweden
E-mail: peter.olsen@su.se, eric@sigridthx.com, bjorn.akermark@su.se

Abstract

The present work shows that it is possible to ring-open cyclic carbonates with unprotected amino acids in water. Fine tuning of the reaction parameters made it possible to suppress the degree of hydrolysis in relation to aminolysis. This enabled the synthesis of functionally dense carbamates containing alkenes, carboxylic acids, alcohols and thiols after short reaction times at room temperature. When Glycine was used as the nucleophile in the ring-opening with four different five membered cyclic carbonates, containing a plethora of functional groups, the corresponding carbamates could be obtained in excellent yields (>90%) without the need for any further purification. Furthermore, the orthogonality of the transformation was explored through ring-opening of divinylenecarbonate with unprotected amino acids equipped with nucleophilic side chains, such as serine and cysteine. In these cases the reaction selectively produced the desired carbamate, in 70 and 50% yield respectively. The synthetic design provides an inexpensive and scalable protocol towards highly functionalized building blocks that are envisioned to find applications in both the small and macromolecular arena.

link http://pubs.rsc.org/en/Content/ArticleLanding/2018/GC/C7GC02862H?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2FGC+%28RSC+-+Green+Chem.+latest+articles%29#!divAbstract

Affiliation

Stockholm University

Location

Stockholm, Sweden

Department

Department of Organic Chemistry

Position

PostDoc Position

Research experience

Jun 2010–Feb 2016

PhD Student

KTH Royal Institute of Technology · Department of Fibre and Polymer Technology

Sweden · Stockholm

Björn Åkermark

Education

Jan 1962–Jun 1967

KTH Royal Institute of Technology

Organic Chemistry and Catalysis · PhD

Sweden · Stockholm

Awards & achievements

Jun 2009

Award: Bror Holmberg Medal, Swedish Chemical Society
Feb 2009

Award: Ulla and Stig Holmquists Prize, Uppsala University
Oct 1997

Award: Dr hc, University D´Aix-Marseille
Oct 1991

Award: KTH Prize for Excellence in Teaching
Oct 1978

Award: Arrhenius Medal, Swedish Chemical Society
Aug 1977

Scholarship: Zorn Fellowship, Swden America Foundation
Nov 1976

Award: Letterstedt Award, Roy Swed. Acad. of Science

Dr. Eric Johnston, Ph.D.

Chief Technology Officer

Dr. Eric V. Johnston obtained his Master of Science degree in 2008 at the Department of Organic Chemistry, Stockholm University, Sweden. In the same year, he started his graduate studies under the supervision of Prof. Jan-Erling Bäckvall. During his PhD, he worked on the development of new homogeneous and heterogeneous transition-metal catalysts.

After receiving his PhD in 2012, he joined Prof. Samuel J. Danishefskys research group at Memorial Sloan-Kettering Cancer Center, New York, USA as a postdoctoral fellow supported by The Swedish Research Council. Here he was engaged in the total chemical synthesis of glycolsylated proteins that play important roles in modern cancer treatment.

In 2014 he returned to the Department of Organic Chemistry at Stockholm University to establish his own group. The goal of his research is to contribute new advances to the strategy and methodology for the preparation of synthetic macromolecules such as proteins, glycopeptides, sequence and length-controlled polymers. He is also a Co-Supervisor for Prof. Björn Åkermarks research group, which aims at studying and developing new homogeneous, as well as heterogeneous, water oxidation catalysts.

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Transition-Metal-Free Cross-Coupling of Aryl and Heteroaryl Thiols with Arylzinc Reagents

spectroscopy, SYNTHESIS, Uncategorized Comments Off

Nov 092017

Zhong-Xia WANG

N,N-dimethyl-4-biphenylamine

(1) N,N-dimethyl-[1,1′-biphenyl]-4-amine (3a) 5,6

Elute: EtOAc/petroleum ether: 1/100 (v/v), white solid, yield 97.8 mg (99%).

1H NMR (400 MHz, CDCl3): δ 7.56 (d, J = 7.8 Hz, 2H), 7.51 (d, J = 8.8 Hz, 2H), 7.40 (t, J = 7.7 Hz, 2H), 7.30–7.21 (m, 1H), 6.81 (d, J = 8.8 Hz, 2H), 3.00 (s, 6H).

13C NMR (101 MHz, CDCl3): δ 150.09, 141.34, 129.37, 128.78, 127.84, 126.43, 126.12, 112.90, 40.97.

5 Yang, X.; Wang, Z.-X. Organometallics 2014, 33, 5863.

(6) Stibingerova, I.; Voltrova, S.; Kocova, S.; Lindale, M.; Srogl, J. Org. Lett. 2016, 18, 312.

Transition-Metal-Free Cross-Coupling of Aryl and Heteroaryl Thiols with Arylzinc Reagents

Bo Yang^† and Zhong-Xia Wang^*^†^‡

^† CAS Key Laboratory of Soft Matter Chemistry, Hefei National Laboratory for Physical Sciences at Microscale and Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China

^‡ Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, P. R. China

Org. Lett., Article ASAP

DOI: 10.1021/acs.orglett.7b03145

*E-mail: zxwang@ustc.edu.cn.

Abstract

Cross-coupling of (hetero)arylthiols with arylzinc reagents via C–S cleavage was performed under transition-metal-free conditions. The reaction displays a wide scope of substrates and high functional-group tolerance. Electron-rich and -deficient (hetero)arylthiols and arylzinc reagents can be employed in this transformation. Mg²⁺ and Li⁺ ions were demonstrated to facilitate the reaction.

In summary, we developed a transition-metal-free coupling reaction of (hetero)arylthiols with arylzinc reagents to form bi(hetero)aryls. The reaction exhibited wide substrate scope and good compatibility of functional groups. Electron-rich and -poor aryl or heteroaryl thiols can be converted. Various arylzinc reagents, including electron-rich and electron-poor reagents, can be employed as the coupling partners. Preliminary mechanistic studies suggest a nucleophilic aromatic substitution pathway, and Mg²⁺ and Li⁺ ions play important roles in the process of reaction. This study provides an example of S^2– as a leaving group in an aromatic system and an effective methodology for the synthesis of bi(hetero)aryls including pharmaceutical molecules without transition-metal impurities.

Zhong-Xia WANG


	Department：	Department of Chemistry
	Mailing Address：	Department of Chemistry, University of Science and Technology of China, 96 Jinzhai Rd, Hefei, Anhui, 230026, PR China
	Postal Code：	230026
	Phone：	+86-551-63603043
	Fax：
	Homepage：	http://chem.ustc.edu.cn/szdw_16/bd/201210/t20121023_142877.html

Zhong-Xia Wang is a professor in the Department of Chemistry at the University of Science and Technology 
of China. He received his BS degree (1983) and MS degree (1986) from Nankai University, 
and PhD degree (1997) from the University of Sussex, UK. Since July 1986, Wang has been working 
at the University of Science and Technology of China (USTC) successively as Assistant, 
Lecturer, Associate Professor, and Professor. From Aug. 1993 to Oct. 1996, he pursued his doctoral 
studies at the University of Sussex, UK, and from Oct. 1999 to Oct. 2000, he was a Research Associate 
at the Chinese University of Hong Kong.

 学 系
Department of Chemistry

Predicts

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http://pubs.acs.org/doi/10.1021/acs.orglett.7b03145

“ALL FOR DRUGS” CATERS TO EDUCATION GLOBALLY, No commercial exploits are done or advertisements added by me. This is a compilation for educational purposes only. 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

An efficient green protocol for the synthesis of tetra-substituted imidazoles catalyzed by zeolite BEA: effect of surface acidity and polarity of zeolite

spectroscopy, SYNTHESIS, Uncategorized Comments Off

Nov 032017

Image result for Kalpana C. Maheria sv

1-benzyl-2, 4, 5-triphenyl-1H-imidazole

. 1-Benzyl-2,4,5-triphenyl-1H-imidazole (5a, n = 1).

Off-white solid; m.p.: 160–162 °C;

anal. calcd. for C28H22N2: C, 87.01, H, 5.74, N, 7.25%. Found: C, 87.13, H, 5.70, N, 7.19%;

UV (λmax, ethanol) = 280 nm;

FT-IR (KBr, cm−1 ): 3060 (C–H stretch), 3031, 1600 (CN), 1497, 1483, 1447 (CC), 1352 (C–N stretch), 769, 697 (C–H band);

1 H NMR (400 MHz, DMSO): 5.16 (s, 2H, CH2), 6.74–7.67 (m, 20H, Ar–H) ppm;

13C NMR (100 MHz, DMSO): 47.6 (CH2, C8), 125.1 (CHarom, C28), 126.0 (CHarom, C26), 126.2 (CHarom, C30), 126.4 (CHarom, C11), 127.0 (CHarom, C15), 127.1 (CHarom, C16), 127.7 (CHarom, C20), 128.0 (CHarom, C21), 128.1 (CHarom, C25), 128.4 (CHarom, C13), 128.5 (CHarom, C18), 128.6 (CHarom, C27), 128.8 (C1), 128.8 (CHarom, C12), 128.9 (CHarom, C14), 130.1 (CHarom, C17), 130.3 (CHarom, C19), 130.5 (CHarom, C22), 130.7 (CHarom, C24), 131.0 (CHarom, C29), 134.4 (CHarom, C9), 135.1 (CHarom, C23), 136.8 (CHarom, C7), 137.0 (CHarom, C10), 137.2 (CHarom, C6), 145.4 (C2), 147.0 (C4) ppm;

MS: m/z = 387.5 (M + H)+

An efficient green protocol for the synthesis of tetra-substituted imidazoles catalyzed by zeolite BEA: effect of surface acidity and polarity of zeolite

Jenifer J. Gabla,^a Sunil R. Mistry^b and Kalpana C. Maheria*^a

Jenifer J Gabla

S V National Institute of Technology, India

Jenifer J Gabla has obtained her MSc degree in Organic Chemistry, in the year 2013 from Uka Tarsadia University, Bardoli, Gujarat. She is currently pursuing her PhD in the area of solid acid catalyzed multicomponent reactions for the synthesis of biologically active drug molecules, at Applied Chemistry Department (ACD), S. V. National Institute of Technology (SVNIT) under the guidance of Kalpana Maheria, Assistant Professor & Head, ACD, SVNIT, Surat, Gujarat, India. Her research focuses on development of novel zeolite based catalytic materials and exploring their utility in the green process development for the synthesis of medicinal compounds. She has presented her research in several national and international conferences.

Kalpana C. Maheria

*Corresponding authors

^aApplied Chemistry Department, S. V. National Institute of Technology, Ichchhanath, Surat – 395007, India
E-mail:kcmaheria@gmail.com

^bMandvi Science College, Mandvi – 394160, Surat, India

Abstract

In the present study, the catalytic activity of various medium (H-ZSM-5) and large pore (H-BEA, H-Y, H-MOR) zeolites were studied as solid acid catalysts. The zeolite H-BEA is found to be an efficient catalyst for the synthesis of 1-benzyl-2,4,5-triphenyl-1H-imidazoles through one-pot, 4-component reaction (4-CR) between benzil, NH₄OAc, substituted aromatic aldehydes and benzyl amine. The hydrophobicity, Si/Al ratio and acidic properties of zeolite BEA were well improved by controlled dealumination. The synthesized materials were characterized by various characterization techniques such as XRD, ICP-OES, BET, NH₃-TPD, FT-IR, pyridine FT-IR, ²⁷Al and ¹H MAS NMR. It has been observed that the dealumination of the parent zeolite H-BEA (12) results in the enhanced strength of Brønsted acidity up to a certain Si/Al ratio which is attributed to the inductive effect of Lewis acidic EFAl species, leading to the higher activity of the zeolite BEA (15) catalyst towards the synthesis of 1-benzyl-2,4,5-triphenyl-1H-imidazoles under thermal solvent-free conditions with good to excellent yields. Using the present catalytic synthetic protocol, diverse tetra-substituted imidazoles, which are among the significant biologically active scaffolds, were synthesized in high yield within a shorter reaction time. The effect of polarity, surface acidity and extra framework Al species of the catalysts has been well demonstrated by means of pyridine FT-IR, and ²⁷Al and ¹H MAS NMR. The solvent-free synthetic protocol makes the process environmentally benign and economically viable.

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S. V. National Institute of Technology, Ichchhanath, Surat

Mandvi Science College, Mandvi – 394160, Surat, India

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Towards nitrile-substituted cyclopropanes – a slow-release protocol for safe and scalable applications of diazo acetonitrile

spectroscopy, SYNTHESIS Comments Off

Apr 222017

Towards nitrile-substituted cyclopropanes – a slow-release protocol for safe and scalable applications of diazo acetonitrile

Green Chem., 2017, Advance Article

DOI: 10.1039/C7GC00602K, Communication

Katharina J. Hock, Robin Spitzner, Rene M. Koenigs
Applications of diazo acetonitrile in cyclopropa(e)nation reactions are realized in a slow-release protocol with bench-stable reagents. Cyclopropyl nitriles are obtained in one step in good diastereoselectivity on a gram-scale providing an efficient entry into this class of fragrances and drug-like molecules.

trans-2-phenylcyclopropane-1-carbonitrile

colorless solid (46 mg, 81%);

m.p. = 29°C;

1 H-NMR (600 MHz, CDCl3): δ = 7.34 – 7.30 (m, 2H), 7.28 – 7.24 (m, 1H), 7.12 – 7.08 (m, 2H), 2.63 (ddd, J = 9.2, 6.7, 4.7 Hz, 1H), 1.62 (dt, J = 9.2, 5.4 Hz, 1H), 1.55 (ddd, J = 8.7, 5.5, 4.8 Hz, 1H), 1.45 (ddd, J = 8.8, 6.7, 5.3 Hz, 1H);

13C-NMR (151 MHz, CDCl3): δ = 137.55, 128.76, 127.41, 126.31, 121.05, 24.90, 15.24, 6.63;

HRMS (ESI): m/z calc. for [C10H9NNa]: 166.06272, found 166.06276;

IR (KBr): νmax/cm-1 = 3044, 2235, 2098, 1761, 1600, 1461, 1220, 1051, 920, 705.

The analytical data is in correspondence with the literature [2]

[2] M. Gao, N. N. Patwardhan, P. R. Carlier, J. Am. Chem. Soc., 2013, 135 (38), 14390–14400

http://pubs.rsc.org/en/Content/ArticleLanding/2017/GC/C7GC00602K?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2FGC+%28RSC+-+Green+Chem.+latest+articles%29#!divAbstract

Towards nitrile-substituted cyclopropanes – a slow-release protocol for safe and scalable applications of diazo acetonitrile

Katharina J. Hock,^a Robin Spitzner^a and Rene M. Koenigs*^a

Author affiliations

*Corresponding authors

^aRWTH Aachen University, Institute of Organic Chemistry, Landoltweg 1, D-52074 Aachen, Germany
E-mail: rene.koenigs@rwth-aachen.de

Abstract

Diazo acetonitrile has long been neglected despite its high value in organic synthesis due to a high risk of explosions. Herein, we report our efforts towards the transient and safe generation of this diazo compound, its applications in iron catalyzed cyclopropanation and cyclopropenation reactions and the gram-scale synthesis of cyclopropyl nitriles.