4-CHLORO-2-METHYL-PYRIDINE 1-OXIDE synthesis

5synthesis methods

Product Name:4-CHLORO-2-METHYL-PYRIDINE 1-OXIDE
CAS Number:696-08-2
Molecular formula:C6H6ClNO
Molecular Weight:143.57

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Yield:696-08-2 99%

Reaction Conditions:

Stage #1: 4-chIoro-2-methylpyridinewith dihydrogen peroxide;urea in tetrahydrofuran at 0;
Stage #2: with trifluoroacetic anhydride in tetrahydrofuran at 20;

Steps:

1.I.b

b. PREPARATION OF 4-CHLORO-2-METHYLPYRIDINE 1-OXIDE (METHOD 2).[00397] 4-Chloro-2-methylpyridine (5.0 g, 39 mmol, 1.0 eq) and hydrogen peroxide-urea adduct (7.37 g, 78.4 mmol, 2.00 eq) were dissolved in THF (196 mL) and cooled to 0 °C. Trifluoroacetic anhydride (12 mL, 86.3 mmol, 2.2 eq) was added dropwise over 15 minutes and the reaction was allowed to warm to room temperature. After determination of the completion of the reaction by LCMS (approximately 45 minutes), the reaction was cooled to 0 °C and quenched with a 10% aqueous solution of NaS₂0₃. The reaction was extracted with EtOAc (3x), dried (MgS0₄), filtered and concentrated in vacuo. Purification by flash chromatography on silica gel afforded 5.63 g (99%) of the title compound as a white solid.

References:

WO2012/118563,2012,A2 Location in patent:Page/Page column 135