2-bromo-5-methyl-1,3,4-oxadiazole synthesis

Yield:864750-58-3 31%

Reaction Conditions:

with tert.-butylnitrite;copper(ll) bromide in acetonitrile at 0 - 65; for 3 h;Inert atmosphere;

Steps:

2-bromo-5 -methyl- 1 ,3,4-oxadiazole
Tert-butyl nitrie (4.7 g, 40.4 mmol) was added into a stirred mixture of 5-methyl-l,3,4- oxadiazol-2-amine (2 g, 20.2 mmol) and CuBr2 (6.7 g, 30.3 mmol) in MeCN at 0 °C under nitrogen atmosphere. The resulting mixture was heated to 65 °C and stirred for 3 hours. After cooled to rt, the reaction mixture was diluted with LhO (100 mL), and extracted with EA (3 x 100 mL). The combined organic layers were washed with brine (200 mL), dried over anhydrous Na2SC>4, and concentrated under vacuum. The residue was purified by column chromatography (EA in PE from 0% to 50%) to afford 2-bromo-5 -methyl- 1,3,4- oxadiazole (1 g, 31% yield) as a yellow solid. LCMS (m/z) 163 (M+EC), retention time: 0.390 min. LC/MS Method 13.

References:

GLAXOSMITHKLINE INTELLECTUAL PROPERTY DEVELOPMENT LIMITED;FOX, Ryan Michael;HARRIS, Philip Anthony;HOLENZ, Joerg;SEEFELD, Mark Andrew;ZHOU, Ding WO2019/130230, 2019, A1 Location in patent:Page/Page column 70

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