MY PICTURE MY PICTURE

Pakamas Tongcharoensirikul Jenkins

Department of Chemistry
College of Arts and Sciences
102 Hurtig Hall, 360 Huntington Avenue
Northeastern University
Boston, MA 02115

p.tongcharoensirikul@neu.edu

https://members.tripod.com/pak_t/index.html


Key Words

Education; Synthetic Organic Chemistry; Biochemistry; Organic Photochemistry; Analytical Instruments; NMR Spectrometer; Mass Spectrometer; Molecular modeling.

Objective

A teaching position or a challenging research position in synthetic organic chemistry; biochemistry; organic photochemistry; or polymer chemistry or in the fields of NMR Spectrometer or Mass Spectrometer.

Education, Languages-Hobbies, Professional Skills, Work Experiences, Training, Professional Society, Awards, Presentations, Publications, References,


Education

October 1999-Present Postdoctoral fellow
Department of Pharmaceutical Sciences
The University of Montana Missoula, MT 59812
awarded by The American Heart Association
Research: 1. Asymmetric Synthesis of alpha-Amino Phosphonothioic Acid
2. Synthesis of Boronic Acid Derivatives as Glutamate Vesicular Transporter and Receptor Inhibitor Analogs
Advisor: Professor Charles M. Thompson, Ph.D.
August 1990-February 1999 Ph.D. Organic Chemistry
Department of Chemistry and Biochemistry
Worcester Polytechnic Institute Worcester, MA 01609
Dissertation: Photochemistry of Substituted Isothiazoles and Thiazoles
Advisor: Professor James W. Pavlik, Ph.D.
June 1984-Nov 1987 M.Sc. Organic Chemistry
Department of Chemistry
Chulalongkorn University , Bangkok, Thailand
M.Sc. Thesis: Copolymerization of Vinyl Acetate with Chlorinated Phenyl Acrylates
Advisor: Professor Supawan Tantayanon, Ph.D.
June 1980-Mar 1984 B.Sc. Chemistry
Department of Chemistry
Chulalongkorn University , Bangkok, Thailand
Senior research: Extraction and Analysis of Strychnine from the seeds of Strychnos nux vomica
Advisor: Professor Somchai Paengpreecha, Ph.D.

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Languages-Hobbies

fluent in English and Thai, working knowledge of Japanese.
watercolor painting, running, playing basketball, dancing.

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Professional Skills

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Work Experiences

October 1999-Present A Postdoctoral fellow at The University of Montana
Research Project: 1. alpha Amino Phosphonothioic Acid
2. Glutamate Vesicular Transporter and Receptor Inhibitor
Advisor: Professor Charles M. Thompson, Ph.D.
May 1999-September 1999 An Instructor at Department of Chemistry, Srinakarinwirot University
January 1999-May 1999 A Researcher at Department of Chemistry, Chulalongkorn University
August 1996-May 1998 An Instructor at Department of Chemistry and Biochemistry, WPI
August 1990-May 1996 A Teaching Assistant at Department of Chemistry and Biochemistry, WPI
September 1989-August 1990 A Researcher at Kyoto University, Kyoto, Japan
Research Project: Ruthenium Complex Catalyst of C-H Insertion
Advisor: Professor Yoshihisa Watanabe, Ph.D.
May 1988-September 1989 A Researcher and an instructor for petrochemistry and spectroscopy courses (junior and senior theoretical courses)
Petroleum and Petrochemical College,
Chulalongkorn University, Bangkok, Thailand.
May 1984-September 1989 An analyst at K. Kosmic Holding Co., Ltd., Bangkok, Thailand
Quality control of products such as mouth wash, propylene oxide, malt in beer manufacturing.

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Training

June 1999 Chemical Safety: Management Incidents in University

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Professional Society

August 1990-present American Chemical Society (ACS)

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Awards

June 2000-November 2001 The American Heart Association Postdoctoral Fellowship Award
The proposal was written by Pakamas and was awarded "$62400"
February 2003-present The Army Medical Research Postdoctoral Fellowship Award
The proposal was written by Pakamas and was awarded "$98000"
1999 Sigma Xi Ph.D. Research Award Nomination
1995 The American Institute of Chemist Graduate Student Award
1994 Teaching Assistant of The Year Award, Worcester Polytechnic Institute
1993 Phi Lambda Upsilon, National Honorary Chemical Society

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Presentations

  1. J. W. Pavlik and P. Tongcharoensirikul, "Phototransposition Chemistry of Phenylisothiazoles and Phenylthiazoles," Paper No. 126, 22nd Northeast Regional Meeting of the American Chemical Society, Syracuse, NY, June 22 1992.
  2. J. W. Pavlik, C. R. Pandit and Pakamas Tongcharoensirikul, "Phototransposition Chemistry of the Thiazole-Isothiazole Heterocyclic System," Poster No. 192, 14th IUPAC Symposium on Photochemistry, K. U. Leuven, Leuven, Belgium, July 19-25, 1992.
  3. J. W. Pavlik, P. Tongcharoensirikul and K. M. French, "Phototransposition Chemistry of Phenylisothiazoles and Phenylthiazoles," Poster No. 47, 5th Inter-American Photochemical Society Winter Conference, Clearwater Beach, FL, January, 1993.
  4. J. W. Pavlik, P. Tongcharoensirikul and K. M. French, "Phototransposition Chemistry of the Phenylisothiazole-Phenylthiazole System," Poster No. 193, 23 rd Northeast Regional Meeting of the American Chemical Society, Boston, MA, June 24, 1993.
  5. J. W. Pavlik, P. Tongcharoensirikul and K. M. French, "Phototransposition Mechanisms for Phenylisothiazoles and Phenylthiazoles in Benzene Solvent," Paper No. 270, 206th National Meeting of the American Chemical Society, Chicago, IL, August 25, 1993.
  6. J. W. Pavlik, P. Tongcharoensirikul and K. M. French, "Phototransposition of Phenylisothiazoles, The P4 Pathway," Paper No. 126, 24th Northeast Regional Meeting of the American Chemical Society, Burlington, VT, June 21, 1994.
  7. J. W. Pavlik and P. Tongcharoensirikul, "Phototransposition Chemistry of Phenylisothiazoles and Phenylthiazoles," Poster No. 129, 15th IUPAC Symposium on Photochemistry, Prague, Czech Republic, July 17-22, 1994.
  8. J. W. Pavlik, P. Tongcharoensirikul and K. M. French, "Phototransposition Chemistry of Phenylisothiazoles, The P4 Permutation Pathway," Poster No. 43, 7th Inter-American Photochemical Society Winter Conference, Clearwater Beach, FL, January, 1995.
  9. P. Tongcharoensirikul and J. W. Pavlik, "Trapping of Nitrile and Isocyanide Intermediates in the Isothiazole to Thiazole Phototransposition," Paper No. 275, 25th Northeast regional Meeting of the American Chemical Society, Rochester, NY, October 21-25, 1995.
  10. P. Tongcharoensirikul and J. W. Pavlik, "Photochemistry of 4-Substituted Isothiazoles," Paper No. 114, 27th Northeast Regional Meeting of the American Chemical Society, Saratoga Springs, NY, June 22-25, 1997.
  11. P. Tongcharoensirikul, J.A. Trautman, A.I. Suarez, and C.M. Thompson, "Stereoselective Synthesis of Substituted alpha-Aminophosphonothionates, Northwest & Rocky Mountain ACS Joint Regional Meeting, Idaho Falls, ID, June 15-17, 2000.
  12. P. Tongcharoensirikul, T. Voelker, A. Suarez, and C. M. Thompson, "Synthesis of enantioenriched APTA’s and preliminary screening as matrix metalloproteinase inhibitors" 222nd ACS National Meeting, Chicago, Illinois, August 26-30, 2001.
  13. P. Tongcharoensirikul, R. Bridges and C. M. Thompson, "Boronic acid analogs as selective inhibitors of glutamate receptors and transporters" 222nd ACS National Meeting, Chicago, Illinois, August 26-30, 2001.
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Publications

  1. Pavlik, J. W.; Tongcharoensirikul, P.; Bird, N. P.; Day, A. C.; Barltrop, J. "A. Phototransposition Chemistry of Phenylisothiazoles and Phenylthiazoles. 1.Interconversions in Benzene Solution" J. Am. Chem. Soc. 1994, 116, 2292-2300.
  2. Pavlik, J. W.; Tongcharoensirikul, P.; French, K. M. "Phototransposition Chemistry of 4-Substituted Isothiazoles. The P4 Permutation Pathway" J. Org. Chem. 1998, 63, 5592-5603.
  3. Pavlik, J. W.; Tongcharoensirikul, P. "Photochemistry of 3- and 5-Phenylisothiazoles. Competing Phototransposition Pathways" J. Org. Chem. 2000, 65, 3626-3632.
  4. Trautmann, J.; Suarez, A. I.; Tongcharoensirikul, P.; Muth, G. W.; Thompson, C. M. "A Facile Route to Substituted Dimethoxy Phosphonothionates Using Dimethyl Thiophosphite" Phosphorus, Sulfur, and Silicon and the Related Elements manuscript accepted.
  5. Tongcharoensirikul, P.; Suarez, A. I.; Thompson, C. M. "Effect of Chiral Auxiliaries on the Stereoselective Addition of Dimethyl Thiophosphite to Imines" manuscript in preparation to submit to The Journal of Organic Chemistry.
  6. Tongcharoensirikul, P.; Fussell, K.; Williamson, D.; Voelker, T.; Thompson, C. M. "Development of A Novel Rapid High-Performance Liquid Chromatography-Mass Spectrometry Assay for Thermolysin Activity" manuscript in preparation to submit to Analytical Biochemistry.
  7. Tongcharoensirikul, P.; Fussell, K.; Williamson, D.; Voelker, T.; Thompson, C. M.
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Goals for this year (2001)

  1. 2-3 publications
  2. ACS National Presentation in Chicago
  3. looking for a job that I am interested in, in chemistry field that has emphasis in biological interest

References

  1. Professor James W. Pavlik, Ph.D.
    Department of Chemistry and Biochemistry
    Worcester Polytechnic Institute
    100 Institute Road,
    Worcester, MA 01609-2280, USA
    Phone: (508)831-5283
    e-mail: jwpavlik@wpi.edu
  2. Professor Charles, M. Thompson, Ph.D.
    Department of Pharmaceutical Sciences
    School of Pharmacy and Allied Health
    The University on Montana,
    Missoula, MT 59812-1552, USA
    Phone: (406)243-4643
    e-mail: cmthomp@selway.umt.edu
  3. Professor James P. Dittami, Ph.D.
    Department of Chemistry and Biochemistry
    100 Institute Road,
    Worcester, MA 01609-2280, USA
    Phone: (508)831-5263
    e-mail: jdittami@wpi.edu
  4. Dr. Peter Ziegler
    Northeast Office
    Bruker BioSpin Corporation
    15 Fortune Drive, Manning Park
    Billerica, MA 01821
    Phone: (978) 667-9580
    Fax: (978) 667-0985
  5. Professor Ladislav H. Berka, Ph.D.
    Department of Chemistry and Biochemistry
    100 Institute Road,
    Worcester, MA 01609-2280, USA
    Phone: (508)831-5444
    e-mail: lhberka@wpi.edu

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mail to:pak_t@mailcity.com

Abstract

Phenylthiazoles 1-3 and phenylisothiazoles 4-6 undergo phototransposition in benzene solvent mainly by P5, P6, and P7 permutation pathways. 4-Phenylisothiazole (5) and 5-phenylisothiazole (6) also transpose via a P4 permutation process to yield 4-phenylthiazole (2) and 5-phenylthiazole (3), respectively in less than 1% yield. In benzene saturated with D2O, 2-phenylthiazole (1 and 5-phenylisothiazole (6) each transposes to yield 4-deuterio-3-phenylisothiazole (4-D-4) and 4-phenylthiazole (2) without deuterium incorporation. Irradiation of 4-phenylthiazole (2) under these conditions results in rapid photodeuteration to yield 2-deuterio-4-phenylthiazole (2-D-2), which subsequently phototransposes to 5-deuterio-3-phenylisothiazole (5-D-4). These experimental results can be rationalized by a mechanism involving initial electrocyclic ring closure and sigmatropic shift of sulfur around the four sides of the azetine ring. Rearomatization of each bicyclic intermediate thus allows sulfur to insert into each position in the carbon-nitrogen sequence. As a consequence, these compounds can be divided into a tetrad in which isomers 1, 2, 4, and 6 interconvert mainly via P5, P6, and P7 pathways. Within the tetrad, BC-6, the bicyclic intermediate derived from 5-phenylisothiazole (6), is postulated to undergo deuteration with simultaneous sigmatropic shift of sulfur when the reaction is carried out in benzene-D2O. This mechanistic view provides one coherent interpretation for the observed phototransposition and photodeuteration reactions.

Upon irradiation in the presence of a small quantity of base, 4-substituted isothiazoles undergo photocleavage to yield substituted cyanosulfides, which can be trapped as their benzyl thioether derivatives, and substituted isocyano sulfides. Both products are suggested to arise via initial photocleavage of the sulfur-nitrogen bond, resulting in the formation of a substituted b-thioformylvinyl nitrene, which can rearrange to the observed cyanosulfide, or cyclize to an undetected thioformylazirine. Deprotonation of the azirine leads directly to the isocyanosulfide. The plight of the isocyanosulfide depends on the C-4 substituent. If the substituent is aromatic, the isocyanosulfide is reprotonated at the isocyanide carbon and spontaneously cyclize to a substituted thiazole, the observed transposition product. If the substituent is aliphatic, the isocyanosulfide is reprotonated at the sulfur and the resulting species has a higher energy barrier to cyclization. In these cases, the isocyanosulfides can be observed spectroscopically and can be trapped as their N-formylaminobenzyl thioether derivatives.

Following is the presentation accompanying my thesis defense.