3-(4,4,5,5-Tetramethyl-[1,3,2]dioxaborolan-2-yl)pyridine.

5.........3-pyridylboronic acid pinacol ester
 3-(4,4,5,5-Tetramethyl-[1,3,2]dioxaborolan-2-yl)pyridine.
 Pyridine, 3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-; (329214-79-1)

compd5=  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.

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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Tunis, tunisia
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