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
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
.Tunis, tunisia
With Tarek Chelsea at Av. de la Liberté - Lafayette Tunis.
Past... — at Carthage Land.
Wisem Djerbien at Hay ennasr tunis.
Les Berges du Lac, Tunis, Tunisia
Alstom low-floor trolley, Place de Barcelona, Tunis, Tunisia
Tunis-Carthage International Airport, Tunisia
Republique Station, Metro leger, Tunis, Tunisia
People walk through the town's main avenue, Avenue Habib Bourguiba.
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