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Showing posts with label nmr. Show all posts
Showing posts with label nmr. Show all posts

Thursday 22 June 2017

Efficient and Stereoselective Syntheses of Isomerically Pure 4-Aminotetrahydro-2H-thiopyran 1-Oxide Derivatives

 

trans-4-Aminotetrahydro-2H-thiopyran 1-Oxide Methanesulfonate (trans-3d-MsOH)
Compound ...................afforded trans-3d-MsOH (20 g, 68%) as a white crystalline solid.
1H NMR (300 MHz, DMSO-d6) δ 1.60–1.76 (2H, m), 2.16–2.29 (2H, m), 2.31 (3H, s), 2.68–2.81 (2H, m), 3.13–3.23 (2H, m), 3.27–3.35 (1H, m), 7.86 (3H, brs).
 
13C NMR (75 MHz, D2O) δ 24.98, 38.51, 46.18, 46.84.
 
LCMS m/z calcd for C5H11NOS: 133.06, found 134.1 [M + H].
 
Anal. Calcd for C6H15NO4S2: C, 31.43; H, 6.59; N, 6.11. Found: C, 31.62; H, 6.48; N, 6.19. mp 214–216 °C.
 
cis-4-Aminotetrahydro-2H-thiopyran 1-Oxide Hydrochloride (cis-4d-HCl)
A mixture of .................... to afford cis-4d-HCl (22.5 g, 62%) as a white crystalline solid.
1H NMR (400 MHz, DMSO-d6) δ 1.81–2.00 (2H, m), 2.06–2.24 (2H, m), 2.73 (2H, td, J = 13.6, 3.2 Hz), 2.90–3.01 (2H, m), 3.21 (1H, brs), 8.19 (3H, brs).
 
13C NMR (75 MHz, D2O) δ 19.80, 42.94, 47.34.
 
LCMS m/z calcd for C5H11NOS: 133.06, found 134.1 [M + H]. Anal. Calcd for C5H12NClOS: C, 35.39; H, 7.13; N, 8.26. Found: C, 35.28; H, 6.87; N, 8.26. mp 230–232 °C.
 
Efficient and Stereoselective Syntheses of Isomerically Pure 4-Aminotetrahydro-2H-thiopyran 1-Oxide Derivatives
 Research, Takeda Pharmaceutical Company Ltd., Fujisawa, Kanagawa 251-8555, Japan
 Pharmaceutical Sciences, Takeda Pharmaceutical Company Ltd., Yodogawa-ku, Osaka 532-8686, Japan
Org. Process Res. Dev., Article ASAP
DOI: 10.1021/acs.oprd.7b00147
 
*E-mail: ryo.mizojiri@takeda.com. Phone: +81-466-32-1058 (R.M.)., *E-mail: tetsuji.kawamoto@takeda.com. Phone: +81-466-32-1193 (T.K.).
Abstract Image
Efficient and stereoselective syntheses of isomerically pure 4-aminotetrahydro-2H-thiopyran 1-oxide derivatives have successfully been achieved. Isomerically pure (4-nitrophenyl)sulfonyltetrahydro-2H-thiopyran 1-oxides were identified by X-ray crystallographic analyses, and isomerically pure sulfoxide derivatives were characterized by 1H NMR. An oxidation reaction of tert-butyl(4-nitrophenyl)sulfonyl(tetrahydro-2H-thiopyran-4-yl)carbamate with Oxone provided steric control, affording its trans sulfoxide with high efficiency and selectivity. From the obtained trans sulfoxide derivatives, cis sulfoxide derivatives were synthesized conveniently by a hydrogen chloride catalyzed isomerization.

str1 str2

Tropylium salts as efficient organic Lewis acid catalysts for acetalization and transacetalization reactions in batch and flow

Green Chem., 2017, Advance Article
DOI: 10.1039/C7GC01519D, Communication
D. J. M. Lyons, R. D. Crocker, D. Enders, T. V. Nguyen
Tropylium salts were reported as organic-Lewis acids to efficiently catalyze acetalization reactions in batch and flow.

Tropylium salts as efficient organic Lewis acid catalysts for acetalization and transacetalization reactions in batch and flow

 

Abstract

Acetalization reactions play significant roles in the synthetically important masking chemistry of carbonyl compounds. Herein we demonstrate for the first time that tropylium salts can act as organic Lewis acid catalysts to facilitate acetalization and transacetalization reactions of a wide range of aldehyde substrates. This metal-free method works efficiently in both batch and flow conditions, prompting further future applications of tropylium organocatalysts in green synthesis.

1-(Diethoxymethyl)-4-methylbenzene (4a):
Prepared according to the general procedure from p-tolualdehyde and triethylorthoformate to yield the title compound as a colourless oil (99 mg, 0.50 mmol, quant. yield). 4a
1 H NMR (400 MHz, CDCl3) δ 7.38 (d, J = 8.1 Hz, 2H), 7.18 (d, J = 7.9 Hz, 2H), 5.50 (s, 1H), 3.59 (ddq, J = 35.4, 9.5, 7.1 Hz, 4H), 2.37 (s, 3H), 1.25 (t, J = 7.1 Hz, 6H) ppm;
13C NMR (101 MHz, CDCl3) δ 138.0, 136.3, 128.9, 126.64, 101.7, 61.0, 21.3, 15.3 ppm;
IR (KBr) 2973, 2880, 2327, 2102, 1909, 1740, 1448 cm-1 ;
ESI-MS Anal. Calcd. for 217.1199 C12H18O2Na, found 217.1195
1H NMR
1 H NMR (400 MHz, CDCl3) δ 7.38 (d, J = 8.1 Hz, 2H), 7.18 (d, J = 7.9 Hz, 2H), 5.50 (s, 1H), 3.59 (ddq, J = 35.4, 9.5, 7.1 Hz, 4H), 2.37 (s, 3H), 1.25 (t, J = 7.1 Hz, 6H) ppm;
13c nmr
13C NMR (101 MHz, CDCl3) δ 138.0, 136.3, 128.9, 126.64, 101.7, 61.0, 21.3, 15.3 ppm;
UNSW

Vinh Nguyen

Vinh Nguyen
BE (Hon 1, UNSW), Ph.D (ANU), MRACI CChem
Lecturer and DECRA fellow

Contact details

Phone: +61-2-9385 6167
Email: t.v.nguyen@unsw.edu.au

Office

Room 217 Dalton Building (F12)
School of Chemistry - UNSW
Research Group Website
 

Biographical Details

Dr. Vinh Nguyen (also known as: Thanh Vinh Nguyen or Thanh V. Nguyen on academic publication) was born in Vietnam. After high school, he went to Sydney, Australia to study industrial chemistry at University of New South Wales. He then moved to undertake his PhD in organic chemistry with Professor Michael Sherburn at the Australian National University, Canberra. He had worked to develop new synthetic methodologies for application in natural product synthesis and worked on the design and synthesis of enormoussynthetic host molecules for drug-delivery modelling. After graduating in 2010, he came to work on organocatalysis in Professor Dieter Enders group at the Institute of Organic Chemistry, RWTH Aachen, Germany under the auspices of an Alexander von Humboldt Postdoctoral Fellowship.  In June 2013, he moved to Curtin University (Perth, Australia) to start his own independent research group. In June 2015, he moved again to UNSW (Sydney) to take up a Lecturer/DECRA fellow position at the School of Chemistry. His current research interests are organocatalysis, aromatic cation activation, synthesis of naturally occurring and bioactive compounds, asymmetric synthesis and medicinal chemistry.
Selected Awards and Academic Achievements
  • 2016: The 2016 Athel Beckwith Lectureship from RACI Organic Chemistry Division
  • 2015-2018: ARC Discovery Early Career Researcher Award (DECRA)
  • 2014: Thieme Chemistry Journal Award for outstanding early career academics.
  • 2011 – 2013: Alexander von Humboldt Postdoctoral Fellowship (RWTH Aachen, Germany).
  • 2005: The Era Polymer Prize for “The Best Honor Research Thesis” in Industrial Chemistry – UNSW
  • 2000: Silver medal in the 32nd International Chemistry Olympiad in Copenhagen, Denmark

Research interests

Nguyen’s group focuses their research on development of new synthetic methodologies in organic chemistry, organocatalysis and natural product synthesis.
Aromatic Cation Activation:
A new method for the nucleophilic substitution of alcohols and carboxylic acids and other substrates using aromatic tropylium cation activation has been developed. It demonstrates, for the first time, the synthetic potential of tropylium cations in promoting chemical transformations. (http://pubs.acs.org/doi/abs/10.1021/ol5003972).

Monday 12 June 2017

Fe/ppm Cu nanoparticles as a recyclable catalyst for click reactions in water at room temperature

Fe/ppm Cu nanoparticles as a recyclable catalyst for click reactions in water at room temperature

Green Chem., 2017, 19,2506-2509
DOI: 10.1039/C7GC00883J, Communication
Aurelien Adenot, Evan B. Landstrom, Fabrice Gallou, Bruce H. Lipshutz
Nanomicelles housing a terminal alkyne and azide are delivered to ppm Cu-containing nanoparticles that catalyse click reactions in water at rt.
 

Fe/ppm Cu nanoparticles as a recyclable catalyst for click reactions in water at room temperature

*Corresponding authors

Abstract

New iron-based nanoparticles doped with ppm levels of CuOAc are capable of catalyzing cycloadditions between alkynes and azides to afford triazole-containing products. These reactions take place in water at ambient temperatures, enabled by the presence of nanomicelles that function as a delivery mechanism. The NPs can be easily recycled within the same reaction vessel. Low levels of residual copper are found in the product.
str1
(2) 1-Benzyl-4-phenyl-1H-1,2,3-triazole. Isolated as a white powdery crystal (99%).
Rf = 0.33 (1:3 EtOAc: hexanes).
NMR 1 H (CDCl3, 500 MHz, δ): 7.79-7.81 (m, 2H), 7.66 (s, 1H), 7.37-7.42 (m, 5H), 7.30-7.33 (m, 3H), 5.59 (s, 2H).
Melting point: 123-125 o C.
str1

Monday 5 June 2017

Continuous Microflow Synthesis of Fuel Precursors from Platform Molecules Catalyzed by 1,5,7-Triazabicyclo[4.4.0]dec-5-ene



Abstract Image
The first continuous flow synthesis of C8–C16 alkane fuel precursors from biobased platform molecules is reported. TBD (1,5,7-triazabicyclo[4.4.0]dec-5-ene) was found to be a recyclable and highly efficient organic base catalyst for the aldol condensation of furfural with carbonyl compounds, and the selectivity of mono- or difuryl product can be easily regulated by adjusting the molar ratio of substrates. By means of flow technique, a shorter reaction time, satisfactory output, and continuous preparation are achieved under the present procedure, representing a significant advance over the corresponding batch reaction conditions.

Continuous Microflow Synthesis of Fuel Precursors from Platform Molecules Catalyzed by 1,5,7-Triazabicyclo[4.4.0]dec-5-ene

Tao ShenJingjing TangChenglun TangJinglan WuLinfeng WangChenjie Zhu*§ , and Hanjie Ying§
 College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, China
National Engineering Technique Research Center for Biotechnology, Nanjing 211816, China
§Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing 211816, China
State Key Laboratory of Motor Vehicle Biofuel Technology, Nanyang 473000, China
Org. Process Res. Dev., Article ASAP
DOI: 10.1021/acs.oprd.7b00141

*E-mail: zhucj@njtech.edu.cn. Phone/Fax: +86 25 58139389.
 
1-(furan-2-yl)-2-methylpent-1-en-3-one
1a
3-pentanone (100 mmol, 8.6 g) and furfural (100 mmol, 9.6 g) were diluted with MeOH-H2O to 40 mL in stream 1, catalyst TBD (10 mmol, 1.39 g) were diluted with MeOH-H2O (v/v = 1/1) to 40 mL in stream 2, the two streams was purged in a 0.2 mL/min speed into slit plate mixer and at the 353 K passed tubing reactor. Finally, the product was extracted with EtOAc and water, the obtained organic layer was evaporated and purified by silica gel flash chromatography (25:1 hexane-EtOAc) to provide the analytically pure product for further characterization, the aqueous phase was collected and reused.According to the general procedure afforded 14.92 g (91%) of product 1a, isolated as pale yellow oil;
 
1H NMR (400 MHz, CD3OD) δ 7.62 (d, J = 1.4 Hz, 1H), 7.29 (s, 1H), 6.71 (d, J = 3.5 Hz, 1H), 6.52 (dd, J = 3.4, 1.8 Hz, 1H), 2.71 (q, J = 7.3 Hz, 2H), 2.05 (s, 3H), 1.04 (t, J = 7.3 Hz, 3H).
 
13C NMR (100 MHz, CD3OD) δ 203.5, 153.0, 145.8, 133.8, 126.8, 116.6, 113.3, 31.1, 13.2, 9.2.
 
STR1 STR2 str3
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Saturday 3 June 2017

Synthesis of 2-substituted quinazolines by CsOH-mediated direct aerobic oxidative cyclocondensation of 2-aminoarylmethanols with nitriles in air




Green Chem., 2017, Advance Article
DOI: 10.1039/C7GC00977A, Communication
Song Yao, Kaijing Zhou, Jiabing Wang, Hongen Cao, Lei Yu, Jianzhang Wu, Peihong Qiu, Qing Xu
An atom-efficient synthesis of 2-substituted quinazolines is developed by a CsOH-mediated aerobic oxidative reaction of 2-aminoarylmethanols and nitriles in air.


http://pubs.rsc.org/en/Content/ArticleLanding/2017/GC/C7GC00977A?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2FGC+%28RSC+-+Green+Chem.+latest+articles%29#!divAbstract

Synthesis of 2-substituted quinazolines by CsOH-mediated direct aerobic oxidative cyclocondensation of 2-aminoarylmethanols with nitriles in air

 Author affiliations

Abstract

By using air as the superior oxidant, a highly atom-efficient synthesis of 2-substituted quinazolines is developed by a CsOH-mediated direct aerobic oxidative reaction of the readily available and stable 2-aminoarylmethanols and nitriles. Effectively working as the promoter in the alcohol oxidation, nitrile hydration, and cyclocondensation steps, CsOH is the best base for the reaction. A similar method can also be extended to the synthesis of substituted quinolines starting from methyl ketones instead of nitriles.
Graphical abstract: Synthesis of 2-substituted quinazolines by CsOH-mediated direct aerobic oxidative cyclocondensation of 2-aminoarylmethanols with nitriles in air










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Wednesday 17 May 2017

1-[2-(methylsulfanyl)-10H-phenothiazin-10-yl]ethanone

1-[2-(methylsulfanyl)-10H-phenothiazin-10-yl]ethanone (3): Off-white solid, yield. 93% (218 g),
m. p. 223-226 °C.
1H NMR (400 MHz, CDCl3, δ/ppm): 7.49 (d, 1H, arom H, J = 7.6 Hz), 7.46-7.42 (m, 2H, arom H), 7.36-7.32 (m, 2H, arom H), 7.28-7.22 (m, 1H, arom H), 7.13 (dd, 1H, arom H, J = 8.0 Hz and 1.6 Hz), 2.51 (s, 3H, -SCH3), 2.23 (s, 3H, -COCH3).
13C NMR (100 MHz, DMSO-d6, δ/ppm): 168.36, 139.19, 138.52, 137.74, 132.05, 128.07, 127.97, 127.78, 127.44, 127.19, 126.94, 124.60, 124.51, 22.71, 14.88.
MS m/z (ESI): 288.04 (M+H)+.


Abstract Image
An efficient, practical, and commercially viable manufacturing process was developed with ≥99.7% purity and 31% overall yield (including four chemical reactions and one recrystallization) for an active pharmaceutical ingredient, called Metopimazine (1), an antiemetic drug used to prevent emesis during chemotherapy. The development of two in situ, one-pot methods in the present synthetic route helped to improve the overall yield of 1 (31%) compared with earlier reports (<15%). For the first time, characterization data of API (1), intermediates, and also possible impurities are presented. The key process issues and challenges were addressed effectively and achieved successfully.
Org. Process Res. Dev., Article ASAP
DOI: 10.1021/acs.oprd.7b00052
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Monday 8 May 2017

NMR EXAMPLES TO LEARN, (E)-5-Phenylpent-2-enal with real (lit) and predict data




(E)-5-Phenylpent-2-enal has the following physical and spectroscopic properties: 


1H NMR (500 MHz, CDCl3) δ: 2.66-2.71 (m, 2H), 2.85 (t, J = 7.5 Hz, 2 H), 6.15 (ddt, J = 15.8, 7.8, 1.4 Hz, 1 H), 6.87 (td, J = 15.7, 6.7 Hz, 1 H), 7.20-7.25 (m, 3 H), 7.31-7.34 (m, 2 H), 9.51 (d, J = 7.8 Hz, 1 H). 


13C NMR (125 MHz, CDCl3) δ: 34.3, 34.4, 126.6, 128.5, 128.8, 133.6, 140.4, 157.4, 194.1. 


IR (neat) cm−1: 3064, 3031, 2930, 1685, 1490, 1120. 


HRMS calcd. for C11H12O (MH+): 161.0966, found 161.0964. 


GC-MS (EI) m/z (relative intensity), 160 (8%, M+), 142 (14%), 129 (12%), 116 (75%), 92 (35%), 91 (100%), 77 (18%), 65 (60%), 51 (21%).


Purity by GC: 97% (tR = 10.5 min; conditions same as in Note 7).


The material crystallizes in the freezer and has an approximate melting point of -12 to -14 °C.



1H NMR




13 C NMR




1H NMR AND 13C NMR PREDICT COMING.......









Ferdinand Monoyer’s 181st birthday
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O=C\C=C\CCc1ccccc1

2-pyrazolin-5-one

137-45-1 cas
  • 3-Pyrazolin-5-one (8CI)
  • Pyrazol-3(or 5)-ol (6CI,7CI)
  • 1,2-Dihydro-3H-pyrazol-3-one
  • 1,2-Dihydropyrazol-3-one
  • 1H-Pyrazol-3-ol
  • 1H-Pyrazol-5-ol
  • 3-Hydroxypyrazole
  • 3-Pyrazoline-5-one
  • 3-Pyrazolone
  • 4-Pyrazolin-3-one
  • NSC 520837
  • Pyrazol-3-ol
  • Pyrazol-5-ol

Compound 1: Under stirring, to a solution of 5.81 g (50 mmol) of methyl (2E)-3-methoxyacrylate in methanol (5 mL) was hydrazine hydrate (2.75 g, 55 mmol) added and the mixture was refluxed for 1h. Evaporation under reduced pressure to dryness gave 4.13 g (98%) of a slightly yellowish powder, pure according to 1H NMR spectroscopy.
Melting point: 160–162 °C, crystal modifications starting at ~140 °C, (lit. [12] 162–164 °C).
1H-NMR (300 MHz, DMSO-d6, 28 °C, numbering for 1H-pyrazol-3-ol = form D) [13]: δ= 9.82 (br s, 2H, XH); 7.33 (d, 3 J(H5,H4)= 2.3 Hz, 1H, H5); 5.43 (d, 3 J(H4,H5)= 2.3 Hz, 1H, H4).
13C-NMR (75 MHz, DMSO-d6, 28 °C, numbering for 1H-pyrazol-3-ol = form D) [13]: δ= 161.0 (C3, 2 J(C3,H4)= 3.4 Hz, 3 J(C3,H5)= 9.2 Hz); 130.1 (C5, 1 J = 184.0 Hz, 2 J(C5,H4)= 8.2 Hz); 89.3 (C4, 1 J = 175.6 Hz, 2 J(C4,H5)= 8.7 Hz).
15N-NMR (50 MHz, DMSO-d6, 294 K) [14]: δ= –126.5; –192.0.
MS (m/z, %) [15]: 84 (M+ , 100); 55 (24).
Elemental Analysis: Calculated for C3H4N2O (84.08): C, 42.86%; H, 4.80%; N, 33.32%. Found: C, 42.75%; H, 4.65%; N, 33.15%.
References and /Notes:
1. J. Elguero, In 'Comprehensive Heterocyclic Chemistry: Pyrazoles and their Benzo Derivatives', Vol. 5; A. R. Katritzky and C. W. Rees, Eds., Pergamon Press, Oxford, 1984, 167–303.
2. Stanovnik, B.; Svete, J. Product class 1: Pyrazoles. Science of Synthesis 2002, 12, 15–225.
3. Eller, G. A.; Holzer, W. Heterocycles 2004, 63, 2537–2555.
4. Becker, W.; Eller, G. A.; Holzer, W. Synthesis 2005, 2583–2589.
5. Testa, E.; Fontanella, L. Farmaco 1971, 26, 1017–35.
6. Dorn, H.; Zubek, A. J. Prakt. Chem. 1971, 313, 1118–24.
7. Maywald, V.; Steinmetz, A.; Rack, M.; Gotz, N.; Gotz, R.; Henkelmann, J.; Becker, H.; Aiscar Bayeto, PCT Int. Appl. WO 0031042 A2 2000 (Chem. Abstr., 2000, 133, 4655).
8. Holzer, W.; Hallak, L. Heterocycles 2004, 63, 1311–1334, and references cited therein.
9. Cizmarik, J.; Lycka, A. Pharmazie 1988, 43, 794–795.
10. Holzer, W.; Kautsch, C.; Laggner, C.; Claramunt, R. M.; Perez-Torralba, M.; Alkorta, I.; Elguero, J. Molbank 2004 http://www.mdpi.org/molbank/molbank2006/m464.htm 2 von 3 24.02.2009 12:54 Tetrahedron 2004, 60, 6791–6805.
11. Sackus, A.; Holzer, W. manuscript in preparation.
12. Lingens, F.; Schneider-Bernloehr, H. Liebigs Ann. Chem. 1965, 686, 134–144.
13. The spectrum was obtained on a Varian UnityPlus 300 spectrometer (299.95 MHz for 1H, 75.43 MHz for 13C). The center of the solvent signal was used as an internal standard which was related to TMS with δ 2.49 ppm (1H NMR) and δ 39.5 ppm (13C NMR).
14. The spectrum was obtained on a Bruker Avance 500 spectrometer and was referenced against neat, external nitromethane (coaxial capillary). The signals were not unequivocally assigned to the N atoms. 15. The spectrum was obtained on a Shimadzu QP 1000 instrument (EI, 70eV).
Molbank 2006, M464 http://www.mdpi.net/molbank/ A one-step synthesis of pyrazolone Gernot A. Eller* and Wolfgang Holzer Department of Drug Synthesis, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria Phone: +43-1-4277-55634, e-mail: gernot.eller@univie.ac.at *Author to whom correspondence should be addressed
file:///C:/Users/91200291/Downloads/molbank-2006-M464.pdf
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Patent
Synthesis of lH-pyrazol-3-ol
[0223] To a 100 mL round-bottom flask was added methyl (2E)-3-methoxyprop-2-enoate (11.6 g, 99.90 mmol, 1.00 equiv) and methanol (10.0 mL), followed by the addition of hydrazine hydrate (7.8 mL) dropwise with stirring. The resulting solution was stirred for 90 min at 85°C, then concentrated under vacuum to afford crude lH-pyrazol-3-ol as a white solid.
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Happy Mother's Day 2017!
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