Acetic Anhydride → 2-Chloro-3-nitro-4-acetoxymethylpyridine

Temperature

80 °C

A 4:1 mixture of 2--Chloro-3-nitro-4-picoline-N-oxide and 2-Chloro-3-nitro-4-picoline (7.2g, 0.031mol, based on the N-oxide) was dissolved in acetic anhydride (20 mL) and the solution was heated in a 80° C. oil bath for 70 minutes. The solvents were removed under vacuum and the dark residue was partitioned between methylene chloride (100 mL) and saturated aqueous potassium carbonate (200 mL). The aqueous layer was re-extracted with more methylene chloride (1×50 mL) and the combined methylene chloride layers were dried with magnesium sulfate, filtered and evaporated under vacuum. The crude solid was dissolved in methylene chloride (20 mL) and was loaded onto a silica gel column (E. Merck 60, 230-400 mesh, 4×36 cm). The column was eluted with methylene chloride collecting 25 mL fractions. Fractions 22-48 were combined and evaporated to give substantially pure 2-chloro-3-nitro-4-acetoxymethylpyridine (1.75 g) as a white solid.

1. customThe solvents were removed under vacuum
2. customthe dark residue was partitioned between methylene chloride (100 mL) and saturated aqueous potassium carbonate (200 mL)
3. extractionThe aqueous layer was re-extracted with more methylene chloride (1×50 mL)
4. dry with materialthe combined methylene chloride layers were dried with magnesium sulfate
5. filtrationfiltered
6. customevaporated under vacuum
7. dissolutionThe crude solid was dissolved in methylene chloride (20 mL)
8. washThe column was eluted with methylene chloride collecting 25 mL fractions
9. customevaporated

ORD record

ord-cae9220a26774c6090ecb6e25fdca920

Source dataset

uspto-grants-1996_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05565445