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ChemicalBook CAS DataBase List 4,4'-DIMETHYL-2,2'-BIPYRIDINE 1-OXIDE
81998-03-0

4,4'-DIMETHYL-2,2'-BIPYRIDINE 1-OXIDE synthesis

3synthesis methods
-

Yield:81998-03-0 98%

Reaction Conditions:

with dihydrogen peroxide;trifluoroacetic acid in lithium hydroxide monohydrate at 20;

Steps:

4.3. General procedure for the synthesis of 4,4'-di-R-bipy-N-oxides 5 and 7a-d

General procedure: 30% Aqueous H2O2 (2.25 mL, 22.0 mmol) was slowly added to a solution (suspension in the case of 4a) of 4,4'-di-R-2,2'-bipyridine 2 or 4a-d (15.0 mmol) in TFA (10.0 mL). The reaction mixture was stirred at ambient temperature for 2-4 h (TLC monitoring) and diluted with water (60 mL). The precipitated 7a was filtered off, washed successively with water and acetone, dried in air and used in subsequent reactions without further purification. For isolationof 5 and 7b-d, pH of the aqueous solution was carefully adjusted to 7 with 5 M aqueous NaOH and the products were extracted with CHCl3 (320 mL). The combined extracts were dried over anhydrous MgSO4 and evaporated under reduced pressure (10 Torr). Theresidue was washed with n-hexane (5 mL) affording analytically pure samples of 5 and 7 b-d. 4.3.1. 4,40-Dimethyl-2,20-bipyridine, N-oxide (5). Colorless crystals,yield 2.94 g (98%), mp 94e95 C (lit.15c mp 83e84 C); Rf (Silica gel,eluent CHCl3/MeOH (19:1)) 0.55. The 1H NMR spectra was consistentwith reported data.

References:

Zavozin, Alexander G.;Ignat'ev, Nikolai V.;Schulte, Michael;Zlotin, Sergei G. [Tetrahedron,2015,vol. 71,# 45,p. 8551 - 8556]

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