Hydrogen Peroxide → 3,4-Dimethylpyridine 1-oxide

The general procedure of Boekelheide1 for the preparation of hydroxymethylpyridines was used. Thus, a solution of freshly distilled 3,4-lutidine (46.0 g, 0.43 mol) in 120 mL of glacial acetic acid was cooled at 0° C. and then 64 mL of 30% H2O2 was added dropwise. The resulting solution was heated at 75° C. (oil-bath temperature) for 3 h. Another 20 mL of 30% H2O2 was then added and heating was continued for 18 h. Finally, 20 mL of 30% H2O2 was again added and the reaction was kept at 75° C. for another 3 h. The solution was then concentrated to about 100 mL under water-aspirator pressure, 50 mL of H2O was added and the mixture was concentrated to about one half volume. The resulting mixture was cooled (0°-5° C.) and basified to about pH 10 using cold 40% aqeuous NaOH. The mixture was then extracted with CH2Cl2 (5×) and the extract was dried (Na2CO3 +Na2SO4) and concentrated on the roto-vap to give a yellow solution. Dilution of this solution with hexane afforded a solid which was collected by filtration and then dried in vacuo to give 3,4-lutidine-N-oxide (48.0 g, 83%) as an off-white solid.

1. temperatureheating
2. waitthe reaction was kept at 75° C. for another 3 h
3. concentrationThe solution was then concentrated to about 100 mL under water-aspirator pressure, 50 mL of H2O
4. additionwas added
5. concentrationthe mixture was concentrated to about one half volume
6. temperatureThe resulting mixture was cooled (0°-5° C.)
7. extractionThe mixture was then extracted with CH2Cl2 (5×)
8. dry with materialthe extract was dried (Na2CO3 +Na2SO4)
9. concentrationconcentrated on the roto-vap
10. customto give a yellow solution
11. filtrationwas collected by filtration
12. customdried in vacuo

ORD-Eintrag

ord-4af8f3a4bb8a4f39aebfdcb5551bc651

Quelldatensatz

uspto-grants-1987_02

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US04644061