Tout sur les médicaments הכל על תרופות كل شيئ عن الأدوية Все о наркотиках 关于药品的一切 డ్రగ్స్ గురించి అన్ని 마약에 관한 모든 것 Όλα για τα Ναρκωτικά Complete Tracking of Drugs Across the World by Dr Anthony Melvin Crasto, Worldpeacepeaker, worlddrugtracker, PH.D (ICT), MUMBAI, INDIA, Worlddrugtracker, Helping millions, 9 million hits on google on all websites, 2.5 lakh connections on all networks, “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
Keminntek Laboratories is a Hyderabad (India) based Contract Research Organization in Pharmaceutical sector in specific Pharmaceutical Intermediates, Speciality Chemicals, Impurities and Active Pharmaceutical Ingredients. Promoters of Keminntek Laboratories are Young and Dynamic Technocrats and established with a vision to provide a best-in class pharmaceutical services. Keminntek Laboratories would be a value-added and innovative-in –approach business partner. It has a strong talent pool of qualified and experienced scientists drawn from the national and international institutes and industry. It has a capability to synthesize in mg to multi-kg scale.
About Us
Vision
Our vision is to build Keminntek Laboratories into a world class leading pharmaceutical service provider based on innovation while keeping health and prosperity in mind. Imperatively, we will continue our business with high standards of ethics in the interest of society and environment.Mission
We are committed towards improving people’s health through science and innovation. Our mission is to provide better access of the affordable medicines to the patients and positively impact prosperity.
Team
Promoters of this company are very well qualified and experienced personalities in Pharmaceutical sector
We have a team consisting
Ph.Ds from premier Indian Institutes and postdocs from abroad
M. Sc (Chemistry) with 2-12 years pharmaceutical industry experience
Our team expertise lies in process R&D of pharmaceutical intermediates, NCEs (Medicinal Chemistry) development, pharmaceutical impurities, and custom synthesis of specialty chemicals
cancer, new drugs, spectroscopy, SYNTHESISComments Off on Dr. Vinayak Pagar( GUEST BLOGGER) Development of a Povarov Reaction/Carbene Generation Sequence for Alkenyldiazocarbonyl Compounds
Metal-catalyzed cycloadditions of alkenyldiazo reagents are useful tools to access carbo- and heterocycles.[1] These diazo compounds are chemically sensitive toward both Brønsted orLewis acids. Their reported cycloadditions rely heavily on the formation of metal carbenes to initiate regio- and stereoselective [3+n] cycloadditions (n=2–4) with suitable dipolarophiles.[2–4] A noncarbene route was postulated for a few copper-catalyzed cycloadditions of these diazo species, but they resulted in complete diazo decomposition.[3a, 4a, 5] oyle and co-workers reported[4a] a [3+2] cycloaddition of the alkenylrhodium carbene A with imines to give dihydropyrroles (Scheme 1a). We proposed a cycloaddition the tetrahydroquinoline derivatives 3 and 3’, as well as the tetrahydro-1H-benzo[b]azepine species 4. Access to these frameworks are valuable
Access to these frameworks are valuable for the preparation of several bioactive molecules including 2-phenyl-2,3-
dihydroquinolone,[8a] L-689,560,[8b] torcetrapib,[8c] martinellic acid,[8d] OPC-31260,[8e] OPC-51803,[8f] and tetraperalone A (Figure 1).[8g] Their specific biological functions have been well documented.[8]
Spectral data for ethyl 2-diazo-2-(2-phenyl-1,2,3,4-tetrahydroquinolin-4-yl) acetate (2a)
†We thank the National Science Council, Taiwan, for financial support of this work., [*] A. M. Jadhav, V. V. Pagar, Prof. Dr. R.-S. Liu
Department of Chemistry, National Tsing Hua University
Hsinchu (30013) (Taiwan)
E-mail: rsliu@mx.nthu.edu.tw
Abstract
Rings aplenty: A HOTf-catalyzed (Tf=trifluoromethanesulfonyl) Povarov reaction of alkenyldiazo species has been developed and delivers diazo-containing cycloadducts stereoselectively (see scheme). The resulting cycloadducts provide access to six- and seven-membered azacycles through the generation of metal carbenes as well as the functionalization of diazo group.
[1] Selected reviews: a) M. P. Doyle,M. A. McKervy, T. Ye, Modern Catalytic Methods for Organic Synthesis with Diazo Compounds, Wiley, New York, 1998; b) A. Padwa, M. D. Weingarten, Chem. Rev. 1996, 96, 223; c) H. M. L. Davies, J. R. Denton, Chem. Soc. Rev. 2009, 38, 3061; d) M. P. Doyle, R. Duffy, M. Ratnikov, L. Zhou, Chem. Rev. 2010, 110, 704; e) H. M. L. Davies, D. Morton, Chem. Soc. Rev. 2011, 40, 1857; f) Z. Zhang, J. Wang, Tetrahedron
2008, 64, 6577.
[2] Selected examples for carbocyclic cycloadducts, see: a) L. Deng, A. J. Giessert, O. O. Gerlitz, X. Dai, S. T. Diver, H. M. L. Davies, J. Am. Chem. Soc. 2005, 127, 1342; b) H. M. L. Davies, Adv. Cycloaddit. 1999, 5, 119; c) H. M. L. Davies, B. Xing, N. Kong, D. G. Stafford, J. Am. Chem. Soc. 2001, 123, 7461; d) H. M. L. Davies, T. J. Clark, H. D. Smith, J. Org. Chem. 1991, 56, 3819; e) Y. Liu, K. Bakshi, P. Zavalij, M. P. Doyle, Org. Lett. 2010, 12, 4304; f) J. P. Olson, H. M. L. Davies, Org. Lett. 2008, 10, 573.
[3] For oxacyclic cycloadducts, see: a) X. Xu, W.-H. Hu, P. Y. Zavalij, M. P. Doyle, Angew. Chem. 2011, 123, 11348; Angew. Chem. Int. Ed. 2011, 50, 11152; b) M. P. Doyle, W. Hu, D. J. Timmons, Org. Lett. 2001, 3, 3741.
[4] For azacyclic cycloadducts, see selected reviews: a) M. P. Doyle, M. Yan, W. Hu, L. Gronenberg, J. Am. Chem. Soc. 2003, 125, 4692; b) J. Barluenga, G. Lonzi, L. Riesgo, L. A. Lpez, M. Tomas, J. Am. Chem. Soc. 2010, 132, 13200; c) M. Yan, N. Jacobsen, W. Hu, L. S. Gronenberg, M. P. Doyle, J. T. Colyer, D. Bykowski, Angew. Chem. 2004, 116, 6881; Angew. Chem. Int. Ed. 2004, 43, 6713; d) X.Wang, X. Xu, P. Zavalij, M. P. Doyle, J. Am.
Chem. Soc. 2011, 133, 16402; e) Y. Lian, H. M. L. Davies, J. Am. Chem. Soc. 2010, 132, 440; f) X. Xu, M. O. Ratnikov, P. Y. Zavalij, M. P. Doyle, Org. Lett. 2011, 13, 6122; g) V. V. Pagar, A. M. Jadhav, R.-S. Liu, J. Am. Chem. Soc. 2011, 133, 20728; h) R. P. Reddy, H. M. L. Davies, J. Am. Chem. Soc. 2007, 129, 10312.
[5] Y. Qian, X. Xu, X.Wang, P. Zavalij,W. Hu, M. P. Doyle, Angew. Chem. 2012, 124, 6002; Angew. Chem. Int. Ed. 2012, 51, 5900.
[6] Povarov reactions refer to the formal [4+2] cycloadditions of Naryl imines with enol ethers or enamines. See reviews: a) L. S. Povarov, Russ. Chem. Rev. 1967, 36, 656; b) V. V. Kouznetsov, Tetrahedron 2009, 65, 2721; c) D. Bello, R. Ramn, R. Lavilla, Curr. Org. Chem. 2010, 14, 332; d) M. A. McCarrick, Y. D. Wu, K. N. Houk, J. Org. Chem. 1993, 58, 3330; e) A. Whiting, C. M. Windsor, Tetrahedron 1998, 54, 6035.
[7] For Povarov reactions catalyzed by Brønsted acids, see selected examples: a) H. Xu, S. J. Zuend, M. G. Woll, Y. Tao, E. N. Jacobson, Science 2010, 327, 986; b) T. Akiyama, H. Morita, K. Fuchibe, J. Am. Chem. Soc. 2006, 128, 13070; c) H. Liu, G. Dagousset, G. Masson, P. Retailleau, J. Zhu, J. Am. Chem. Soc. 2009, 131, 4598; d) G. Dagousset, J. Zhu, G. Masson, J. Am. Chem. Soc. 2011, 133, 14804; e) H. Ishitani, S. Kobayashi, Tetrahedron Lett. 1996, 37, 7357; f) G. Bergonzini, L. Gramigna, A. Mazzanti, M. Fochi, L. Bernardi, A. Ricci, Chem. Commun.
2010, 46, 327; g) L. He, M. Bekkaye, P. Retailleau, G. Masson, Org. Lett. 2012, 14, 3158.
[8] a) Y. Xia, Z.-Y. Yang, P. Xia, K. F. Bastow, Y. Tachibana, S.-C. Kuo, E. Hamel, T. Hackl, K.-H. Lee, J. Med. Chem. 1998, 41, 1155; b) R.W. Carling, P. D. Leeson, A. M. Moseley, J. D. Smith, K. Saywell, M. D. Trickelbank, J. A. Kemp, G. R. Marshall, A. C. Foster, S. Grimwood, Bioorg. Med. Chem. Lett. 1993, 3, 65;
c) D. B. Damon, R. W. Dugger, R.W. Scott, U.S. Patent 6,689,897, 2004; d) D. A. Powell, R. A. Batey, Org. Lett. 2002, 4, 2913; e) A. Matsuhisa, K. Kikuchi, K. Sakamoto, T. Yatsu, A. Tanaka, Chem. Pharm. Bull. 1999, 47, 329; f) M. Y. Christopher, E. A. Christine, D. M. Ashworth, J. Barnett, A. J. Baxter, J. D. Broadbridge, R. J. Franklin, S. L. Hampton, P. Hudson, J. A. Horton, P. D. Jenkins, A. M. Penson, G. R.W. Pitt, P. Rivire,
P. A. Robson, D. P. Rooker, G. Semple, A. Sheppard, R. M.Haigh, M. B. Roe, J. Med. Chem. 2008, 51, 8124; g) C. Li, X. Li, R. Hong, Org. Lett. 2009, 11, 4036.
About author( Me)
Dr. Vinayak Pagar
Postdoctoral Research Fellow at The Ohio State University
Vinayak Vishnu Pagar was born in Nasik, Maharashtra (India) in 1983. He obtained his BSc and MSc degrees in chemistry from the University of Pune (India) in 2004 and 2006, respectively. From 2006–2010, he worked as Research Associate in pharmaceutical companies like Jubilant Chemsys Ltd. and Ranbaxy Laboratories Ltd. (India). In 2010, he joined the group of Professor Rai-Shung Liu to pursue his PhD degree in National Tsing Hua University (Taiwan) and completed it in 2014. Subsequently, he worked as a postdoctoral fellow in the same group for one year. Currently, he is working as a Research Scientist at The Ohio State University, Columbus, Ohio USA. His research focused on the development of new organic reactions by using transition-metal catalysis such Gold, Silver, Rhodium, Zinc, Cobalt, Nickel and Copper metals which enables mild, diastereoselective, enantioselective and efficient transformations of variety of readily available substrates to wide range of synthetically useful nitrogen and oxygen containing heterocyclic products which are medicinally important. He published his research in a very high impact factor international Journals includes J. Am. Chem. Soc., Angew. Chem. Int. Ed.,J. Org. Chem., Chem- A. Eur. Journal, Org. Biomol. Chem., and Synform (Literature Coverage).
spectroscopy, SYNTHESISComments Off on Towards nitrile-substituted cyclopropanes – a slow-release protocol for safe and scalable applications of diazo acetonitrile
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.
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.
TOFMS: [C13H21NO6 – H+]: calculated 286.1296, found 286.1031(100%).
HPLC conditions were as follows for compound ; Agilent 1100 series, column: YMC J’SPHERE C18 (150 mm X 4.6 mm) 4µm with mobile phases A (0.05% TFA in water) and B (acetonitrile). Detection was at 210 nm, flow was set at 1.0 mL/min, and the temperature was 30 °C (Run time: 45 min). Gradient: 0 min, A = 90%, B = 10%; 5.0 min, A = 90%, B = 10%; 25 min, A = 0%, B = 100%; 30 min, A = 0%, B = 100%, 35 min, A = 90%, B = 10%; 45 min, A = 90%, B = 10%.
TOFMS: [C17H21NO4 + H+]: calculated 304.1543, found 304.1703(100%).
UPLC conditions were as follows for compound 11; Acquity Waters, column: BEH C18 (2.1 mm X 100 mm) 1.7 µm with mobile phases A (0.05% TFA in water) and B (acetonitrile). Detection was at 220 nm, flow was set at 0.4 mL/min, and the temperature was 30 °C (Run time: 9 min). Gradient: 0 min, A = 90%, B = 10%; 0.5 min, A = 90%, B = 10%; 6.0 min, A = 0%, B = 100%; 7.5 min, A = 0%, B = 100%; 7.6 min, A = 90%, B = 10%; 9.0 min, A = 90%, B = 10%.
Hana and co-workers ( Synlett 2010, 18, 2759−2764) from Genentech have developed a single-step procedure for conversion of 2-nitro aromatic amines to benzimidazoles. Addition of ammonium chloride proved necessary as Fe powder and formic acid alone was ineffective for nitro reduction. These conditions were compatible with a variety of functional groups on the aromatic, including boronate esters. The methodology was also extended to nitro aminopyridines but failed to deliver the desired product with isoxazole or pyrazole reactants.
Mild and General One-Pot Reduction and Cyclization of Aromatic and Heteroaromatic 2-Nitroamines to Bicyclic 2H-Imidazoles
Emily J. Hanan*, Bryan K. Chan, Anthony A. Estrada, Daniel G. Shore, Joseph P. Lyssikatos
*Discovery Chemistry, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA, Email: hanan.emilygene.com
E. J. Hanan, B. K. Chan, A. A. Estrada, D. G. Shore, J. P. Lyssikatos, Synlett, 2010, 2759-2764.
A one-pot procedure for the conversion of aromatic and heteroaromatic 2-nitroamines into bicyclic 2H-benzimidazoles employs formic acid, iron powder, and NH4Cl as additive to reduce the nitro group and effect the imidazole cyclization with high-yielding conversions generally within one to two hours. The compatibility with a wide range of functional groups demonstrates the general utility of this procedure.
“ALL FOR DRUGS” CATERS TO EDUCATION GLOBALLY, No commercial exploits are done or advertisements added by me. This article 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
PROCESS, spectroscopy, SYNTHESISComments Off on A catalyst-free 1,3-dipolar cycloaddition of C,N-cyclic azomethine imines and 3-nitroindoles: an easy access to five-ring-fused tetrahydroisoquinolines
We have reported herein a catalyst-free 1,3-dipolar cycloaddition of C,N-cyclic azomethine imines and 3-nitroindoles by which a series of five-ring-fused tetrahydroisoquinolines featuring an indoline scaffold were obtained as single diastereomers in moderate to high yields without any additives under mild conditions. Moreover, the current method provides a novel and convenient approach for the efficient incorporation of two biologically important scaffolds (tetrahydroisoquinoline and indoline).
A catalyst-free 1,3-dipolar cycloaddition of C,N-cyclic azomethine imines and 3-nitroindoles: an easy access to five-ring-fused tetrahydroisoquinolines
aSchool of Life Sciences, Institute of Biochemistry and Molecular Biology, Lanzhou University, Lanzhou 730000, P. R. China E-mail: wangrui@lzu.edu.cn
bState Key Laboratory of Chiroscience, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Kowloon, P. R. China E-mail: bcrwang@polyu.edu.hk
“ALL FOR DRUGS” CATERS TO EDUCATION GLOBALLY, No commercial exploits are done or advertisements added by me. This article 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
Scheme 1. Pfizer’s Commercial Synthesis of sildenafil citrate (Viagra™)
“Green chemistry” refers to the promotion of safe, sustainable, and waste-minimizing chemical processes. The proliferation of green chemistry metrics without any clear consensus on industry standards is a significant barrier to the adoption of green chemistry within the pharmaceutical industry. We propose the Green Aspiration Level™ (GAL) concept as a novel process performance metric that quantifies the environmental impact of producing a specific pharmaceutical agent while taking into account the complexity of the ideal synthetic process for producing the target molecule. Application of the GAL metric will make possible for the first time an assessment of relative greenness of a process, in terms of waste, versus industry standards for the production process of any pharmaceutical. Our recommendations also include a simple methodology for defining process starting points, which is an important aspect of standardizing measurement to ensure that Relative Process Greenness (RPG) comparisons are meaningful. We demonstrate our methodology using Pfizer’s Viagra™ process as an example, and outline aspiration level opportunities for industry and government to dismantle green chemistry barriers.
Overcoming barriers to green chemistry in the pharmaceutical industry – the Green Aspiration Level™ concept
“ALL FOR DRUGS” CATERS TO EDUCATION GLOBALLY, No commercial exploits are done or advertisements added by me. This article 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
///////////green chemistry, pharmaceutical industry
One-step asymmetric synthesis of (R)- and (S)-rasagiline by reductive amination applying imine reductases
Green Chem., 2017, Advance Article DOI: 10.1039/C6GC03023H, Communication
P. Matzel, M. Gand, M. Hohne
Imine reductases (IREDs) show great potential as catalysts for reductive amination of ketones to produce chiral secondary amines.
One-step asymmetric synthesis of (R)- and (S)-rasagiline by reductive amination applying imine reductases
Imine reductases (IREDs) show great potential as catalysts for reductive amination of ketones to produce chiral secondary amines. In this work, we explored this potential and synthesized the pharmaceutically relevant (R)-rasagiline in high yields (up to 81%) and good enantiomeric excess (up to 90% ee) from the ketone precursor. This one-step approach in aqueous medium represents the shortest synthesis route from achiral starting materials. Furthermore, we demonstrate for the first time that tertiary amines also can be accessed by this route, which provides new opportunities for eco-friendly enzymatic asymmetric syntheses of these important molecules.
spectroscopy, SYNTHESIS, UncategorizedComments Off on Synthesis of (E)-2,4-Dinitro-N-((2E,4E)-4-phenyl-5-(pyrrolidin-1-yl)penta-2,4-dienylidene)aniline
(E)-2,4-Dinitro-N-((2E,4E)-4-phenyl-5-(pyrrolidin-1-yl)penta-2,4-dienylidene) aniline dye was prepared in one pot by reaction of premade N-2,4-dinitrophenyl-3-phenylpyridinium chloride (DNPPC) and pyrrolidine in absolute MeOH.
Keywords:
N-2,4-dinitrophenyl-3-phenylpyridinium chloride (DNPPC); photochromic; pyridinium salt
N-2,4-Dinitrophenyl-3-phenylpyridinium chloride (DNPPC) 1 was prepared according to the literature method [1,2,3,4,5,6,7]. Recently, we became interested in the synthesis of photochromic compounds [8,9,10]. The UV-Vis spectra under irradiation of UV light of dye 2 indicate photochromic properties for this molecule. The salt 1 was premade and typically isolated and purified by recrystallization and characterized. To a solution of 1-chloro-2,4-dinitrobenzene (1.42 g, 7.01 mmol) in acetone (10 mL) was added 3-phenylpyridine (1.0 mL, 6.97 mmol). The reaction was heated at reflux for 48 h. The solvent was removed under reduced pressure and the red residue was stirred in hexanes. The precipitated product was collected by vacuum filtration to afford pure pyridinium salt 1 as a reddish brown solid (2.23 g, 6.25 mmol, 90%). 1H NMR (CDCl3, 500 MHz): δ (ppm) 9.9 (s, 1H), 9.4 (d, J = 6.0 Hz, 1H), 9.3 (d, J = 8.3 Hz, 1H), 9.2 (d, J = 2.2 Hz, 1H), 9.0 (dd, J = 8.7, 2.4 Hz, 1H), 8.5-8.6 (m, 2H), 8.0 (d, J = 7.3 Hz, 2H), 7.6- 7.7 (m, 3H); 13C NMR (CDCl3, 125 MHz): δ (ppm) 149.2, 145.6, 144.3, 144.2, 143.0, 139.2, 138.7, 132.5, 132.3, 130.6, 130.2, 129.6, 128.0, 127.6, 121.3; IR (KBr pellet) 3202, 3129, 2994, 2901, 1609 cm-1; m. p. = 182-183 °C; HRMS m/z Calcd for C17H12N3O4+ (M)+ 322.0828, found 322.0836.
Reaction of pyrrolidine with salt (1) leads to the opening of the pyridinium ring and formation of dye 2. This dye was prepared from reaction of salt 1 (0.5 g, 1.4 mmol) in 5 mL absolute MeOH after cooling a reaction mixture to -10oC and keeping at this temperature for 15 min. To this was added pyrrolidine (0.1 g, 1.4 mmol) in 3 mL absolute MeOH over a period of 10 min. The prepared solid was filtered, washed with CH2Cl2, dried and recrystallized from n-hexane to yield 68% (0.37 g, 0.95 mmol) of pure metallic greenish-brown 2,