Acetic Anhydride → 2-Hydroxymethyl-3-methyl-4-(2,2,3,3,3-pentafluoropropoxy)pyridine

Temperature

110 °C

Concentrated sulfuric acid (2 drops) was added to a solution 2,3-dimethyl-4-(2,2,3,3,3-pentafluoropropoxy)-pyridine-1-oxide (2.5 g) in acetic anhydride (8 ml) and the mixture was stirred at 110° C. for 2 hours and then concentrated. The residue was dissolved in methanol (30 ml), 2 N aqueous sodium hydroxide (20 ml) was added, and the mixture was stirred at room temperature for 2 hours. After concentration, water was added to the residue and the mixture was extracted with ethyl acetate. The extract was dried over magnesium sulfate, the solvent was then distilled off, and te residue was applied to a silica gel (50 g) column. Elution with chloroform-methanol (10:1) and recrystallization from isopropyl ether gave 1.6 g of 2-hydroxymethyl-3-methyl-4-(2,2,3,3, 3-pentafluoropropoxy)pyridine as a brown oil.

1. concentrationconcentrated
2. dissolutionThe residue was dissolved in methanol (30 ml)
3. addition2 N aqueous sodium hydroxide (20 ml) was added
4. stirringthe mixture was stirred at room temperature for 2 hours
5. concentrationAfter concentration, water
6. additionwas added to the residue
7. extractionthe mixture was extracted with ethyl acetate
8. dry with materialThe extract was dried over magnesium sulfate
9. distillationthe solvent was then distilled off
10. washElution
11. customwith chloroform-methanol (10:1) and recrystallization from isopropyl ether

ORD record

ord-d56a9f234b74453eaae79dd95b7cda1e

Source dataset

uspto-grants-2001_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06296875B1