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 or 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 the 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-79760a2e2d634cfab19947abbde3edd7

Source dataset

uspto-grants-2004_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06749864B2