2-Picoline-N-oxide

light yellow to brown crystalline low melting mass

2-Picoline N-oxide is used in proteomics research. Also used as pharmaceutical intermediates.

ChEBI: Picoline N-oxide is a member of methylpyridines and a member of pyridine N-oxides.

2-Methylpyridine 1-oxide is a useful building block for organic synthesis.

K2CO3 (20 mmol) and urea peroxide (10 mmol) were dissolved in dry 1,4-dioxane (100 mL), which was then stirred and reacted at room temperature for 1 hour. Trifluoroacetic anhydride (10 mmol) was added dropwise to the mixture below 12 C to bring the mixture back to room temperature. To the reaction mixture was added the corresponding 2-methylpyridine (1 mmol) and the mixture was stirred at 50 C overnight. The 1,4-dioxane was removed by distillation and replaced with dichloromethane, the mixture was washed with water (50 mL) and the resulting organic layer was dried over anhydrous MgSO4, filtered to remove the desiccant and the resulting filtrate was concentrated under vacuum to remove the solvent to give the 2-methylpyridine oxide.

Purify the N-oxide by fractional distillation, and it can be recrystallised from *C6H6/hexane but is hygroscopic. [Bullitt & Maynard J Am Chem Soc 76 1370 1954, Ross et al. J Am Chem Soc 78 3625 1956, IR: Wiley & SlaymAker J Am Chem Soc 79 2233 1957.] The picrate has m 125-126.5o (from EtOH) [Boekelheide & Linn J Am Chem Soc 76 1286 1954]. The phthalate has m 115-116o (from EtOH) [den Hertog et al. Recl Trav Chim Pays-Bas 70 591 1951.]. [Beilstein 20 III/IV 2689, 20/5 V 479.]