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Featured researches published by Richard J. Varsolona.


Organic Letters | 2013

A Highly Convergent and Efficient Synthesis of a Macrocyclic Hepatitis C Virus Protease Inhibitor BI 201302

Xudong Wei; Chutian Shu; Nizar Haddad; Xingzhong Zeng; Nitinchandra D. Patel; Zhulin Tan; Jianxiu Liu; Heewon Lee; Sherry Shen; Scot Campbell; Richard J. Varsolona; Carl A. Busacca; Azad Hossain; Nathan K. Yee; Chris H. Senanayake

A highly convergent large scale synthesis of a 15-membered macrocyclic hepatitis C virus (HCV) protease inhibitor BI 201302 was achieved, in which the key features are the practical macrocyclization by Ru-catalyzed ring-closing metathesis (0.1 mol % Grela catalyst, 0.1-0.2 M concentration) and the efficient sulfone-mediated SNAr reaction.


Journal of Pharmaceutical and Biomedical Analysis | 2010

Study and characterization of crystalline hydrate/polymorph forms of 5,11-dihydro-11-ethyl-5-methyl-8-(2-(1-oxido-4-quinolinyl)ethyl-6H-dipyrido(3,2-B:2',3'-E)(1,4)diazepin-6-one by solid-state NMR and solution NMR.

Nina C. Gonnella; John A. Smoliga; Scot Campbell; Carl A. Busacca; Michael Kenneth Cerreta; Richard J. Varsolona; Daniel L. Norwood

A novel inhibitor of reverse transcriptase was studied by solid-state NMR. Three phases of the compound were examined which included the dihydrate and two anhydrous polymorphs (Form I and Form III). By correlating (1)H and (13)C solution NMR with the solid-state (13)C NMR CP/MAS and CPPI spectral editing experiments, comparative (13)C assignments were made for each phase. Polymorphs of Form I and Form III and the dihydrate were easily distinguished based upon chemical shift patterns of the carbon resonances. The (1)H spin-lattice relaxation times were also measured for each phase which provided information on the mobility and relative crystallinity. The (13)C ssNMR spectrum of Form I showed the presence of a minor component identified as the dihydrate. Weight/percent quantitation of major and minor components in Form I was obtained from integrated intensities of a 50:50 mixture containing weighed amounts of Form I and the pure dihydrate. Comparison of the ssNMR and X-ray powder diffraction techniques is discussed.


Organic Letters | 2005

A superior method for the reduction of secondary phosphine oxides.

Carl A. Busacca; Jon C. Lorenz; Nelu Grinberg; Nizar Haddad; Matt Hrapchak; Bachir Latli; Heewon Lee; Paul Sabila; Anjan Saha; Max Sarvestani; Sherry Shen; Richard J. Varsolona; Xudong Wei; Chris H. Senanayake


Archive | 2011

Crystalline phases of a potent HCV inhibitor

Michael Kenneth Cerreta; John A. Smoliga; Richard J. Varsolona


Tetrahedron Letters | 2008

Preparation of 3-substituted-2-pyridin-2-ylindoles: regioselectivity of Larock’s indole annulation with 2-alkynylpyridines

Frank Roschangar; Jianxiu Liu; Emilie Estanove; Marine Dufour; Sonia Rodriguez; Vittorio Farina; Eugene R. Hickey; Azad Hossain; Paul-James Jones; Heewon Lee; Bruce Z. Lu; Richard J. Varsolona; Jürgen Schröder; Pierre L. Beaulieu; James Gillard; Chris H. Senanayake


Tetrahedron Letters | 2005

A practical synthesis of LFA-1 inhibitors utilizing CuCl-promoted intramolecular cyclization of thiohydantoins

Xiao-Jun Wang; Li Zhang; Yibo Xu; Dhileepkumar Krishnamurthy; Richard J. Varsolona; Laurence J. Nummy; Sherry Shen; Rogelio P. Frutos; Denis Byrne; J.C. Chung; Vittorio Farina; Chris H. Senanayake


Organic Process Research & Development | 2012

A Robust Process for an mGluR5 Negative Allosteric Modulator: Difluoromethylation and Sonogashira Coupling on Large Scale

Jeffrey B. Sperry; Roger Farr; Mahmut Levent; Mousumi Ghosh; Steven M. Hoagland; Richard J. Varsolona; Karen Sutherland


Archive | 2009

Crystalline forms of a 2-thiazolyl- 4-quinolinyl-oxy derivative, a potent hcv inhibitor

Thilo Berkenbusch; Carl A. Busacca; Burkhard Jaeger; Richard J. Varsolona


Organic Process Research & Development | 2011

Practical Large-Scale Preparation of (±)-2-exo-Norbornyl Carboxylic Acid and Its Improved Isolation As the Sodium Salt

Jianxin Gu; Thomas Storz; Frederick Vyverberg; Charles Wu; Richard J. Varsolona; Karen Sutherland


Organic Process Research & Development | 2005

Development of a scalable process for 1-(3,5-dichlorophenyl)-5-iodo-3-methyl-(4-methylbenzyl)-1H-imidazo[1,2-a]imidazol-2-one : A key intermediate for the synthesis of LFA-1 inhibitors

Rogelio P. Frutos; Magnus Eriksson; Xiao-Jun Wang; Denis Byrne; Richard J. Varsolona; Michael Dale Johnson; Lawrence Nummy; Dhileepkumar Krishnamurthy; Chris H. Senanayake

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