Mark S. Jensen

 

Mark Jensen

Group Leader at Scynexis

Raleigh-Durham, North Carolina Area

Pharmaceuticals

LINKS

 https://www.linkedin.com/pub/mark-jensen/8/a28/ab0

Mark S. Jensen, Ph.D., Research Investigator and Group Leader in the Process Research Department at SCYNEXIS. Dr. Jensen worked for Merck in the process research department before moving to SCYNEXIS, where he continues to design and develop novel and efficient routes to early and late stage drug candidates. These processes are used at SCYNEXIS for the production of API for clinical programs. Mark holds a Ph.D. from Oregon State University and was an NIH Postdoctoral Fellow at the University of California, Irvine.

Experience

Group Leader

Scynexis

Research Fellow

Merck

1997 – 2006 (9 years)

Research Fellow

Merck Research Laboratories - Rahway

1997 – 2006 (9 years)

Education

Oregon State University

University of California, Irvine

An Improved Protocol for the Preparation of 3-Pyridyl- and Some Arylboronic Acids

Wenjie Li ,* Dorian P. Nelson ,* Mark S. Jensen , R. Scott Hoerrner , Dongwei Cai , Robert D. Larsen , and Paul J. Reider

Process Research Department, Merck Research Laboratories, P.O. Box 2000, Rahway, New Jersey 07065 wenjie_li@merck.com; dorian_nelson@merck.com

J. Org. Chem., 2002, 67 (15), pp 5394–5397

DOI: 10.1021/jo025792p

Publication Date (Web): June 13, 2002

Copyright © 2002 American Chemical Society

Abstract

3-Pyridylboronic acid was prepared in high yield and bulk quantity from 3-bromopyridine via a protocol of lithium−halogen exchange and “in situ quench”. This technique was further studied and evaluated on other aryl halides in the preparation of arylboronic acids. 

 paper

 http://www.orgsyn.org/demo.aspx?prep=v81p0089

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4

compd4=   The checkers obtained trispyridylboroxin in various hydration levels (0.85 - 1.0 H₂O). A satisfactory melting point for this solid could not be obtained. ¹H NMR pdf (400 MHz, CD₃OD): δ 7.66 (br s, 1H), 8.38 (d, J=6.6, 1H), 8.51 (dd, J=1.2, 4.4, 1H), 8.61 (br s, 1 H). ¹H NMR spectra were complicated in other solvents such as CDCl₃ and DMSO-d₆. Anal Calcd. for C₁₅H₁₂B₃O₃N₃ · 1.0H₂O: C, 54.15; H, 4.24; N, 12.63. Found: C, 53.95; H, 3.91; N, 12.35. Yield based on this formula is 85%. The submitters report obtaining the product in 91% yield.

7


compd7=  The following characterization data was obtained: mp: 122-125°C; IR (KBr pellet): cm⁻¹ 3044, 1568, 1495, 1410, 1338, 1298, 1187, 1126, 1059, 1022, 952, 932, 816, 784, 758, 709, 909, 808, 786, 752, 709, 61; ¹H NMR pdf (500 MHz, CDCl₃): δ 7.45 (ddd, J=0.9, 4.9, 7.9, 1H), 7.60 (dt, J=0.9, 7.9, 1H), 7.75 (ddd, J=1.2, 6.8, 8.3, 1H), 7.90 (dd, J=0.9, 8.1, 1H), 8.00 (dt, J=2.2, 7.8, 1H), 8.15 (d, J=8.4, 1H), 8.32 (d, J=2.3, 1H), 8.68 (dd, J=1.5, 4.9, 1H), 8.97 (d, J=2.1, 1H), 9.15 (d, J=2.1, 1H); ¹³C NMR (126 MHz, CDCl₃) δ 123.8, 127.3, 127.8, 128.0, 129.3, 129.9, 130.6, 133.57, 133.63, 134.6, 147.7, 148.5, 149.27, 149.29; MS (EI, 70 eV): 207 (16), 206 (M+, 100), 205 (40); HRMS (EI) m/z 206.0847, calcd for C₁₄H₁₀N₂ 206.0944. Anal. Calcd for C₁₄H₁₀N₂: C, 81.53; H, 4.89; N, 13.58. Found: C, 81.43; H, 4.86; N, 13.40.


5


compd5= The checkers obtained the product in 74-82% yield in different runs. The product exhibits the following physical properties: mp 102-105°C; IR (KBr pellet) cm⁻¹ 2994, 2968, 2932, 1609, 1572, 1476, 1410, 1361, 1209, 1154, 1063, 1017, 953, 926, 859, 833, 800, 759, 705; ¹H NMR pdf (500 MHz, CDCl₃): δ 1.33 (s, 12H), 7.25 (ddd, J=1.1, 4.9, 7.5, 1H), 8.03 (dt, J=1.8, 7.5, 1H), 8.64 (dd, J=1.9, 4.9, 1H), 8.93 (d, J=1.1, 1H); ¹³C NMR (126 MHz, CDCl₃) δ 24.8, 84.1, 123.0, 142.2, 152.0, 155.5; MS (EI, 70 eV): 205 (M+, 46), 204 (15), 191 (12), 190 (100), 189 (25), 162 (10), 148 (44), 147 (14), 120 (18), 119 (11), 106 (100), 105 (35), 85 (15), 59 (17), 58 (19); HRMS (EI) m/z 205.1280, calcd for C₁₁H₁₆NO₂B 205.1274. Anal. Calcd for : C₁₁H₁₆BO₂N: C, 64.43; H, 7.86; N, 6.83. Found: C, 64.23; H, 7.99; N, 6.88.
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