Sulfuric Acid → 3-Acetyl-6-methylpyridine
Reaction equation
[CH2:1]([C:3]1[CH:4]=[CH:5][C:6]([CH3:9])=[N:7][CH:8]=1)[CH3:2].S(=O)(=O)(O)[OH:11].C(OC(=O)C)(=O)C.C([O-])([O-])=O.[Na+].[Na+].[Cr](O)(O)(=O)=O>O.C(O)(=O)C>[CH3:9][C:6]1[N:7]=[CH:8][C:3]([C:1](=[O:11])[CH3:2])=[CH:4][CH:5]=1Participants
Conditions
- Temperature
- 25 °C
Procedure
5-Ethyl-2-methyl-pyridine (40 g, 0.33 mol) was placed in a three-necked flask immersed in an ice bath and equipped with an efficient mechanical stirrer, a thermometer and a dropping funnel. Sulfuric acid (14.9 ml, 0.26 mol) was added with vigorous stirring. Then acetic acid (47.5 ml), acetic anhydride (46.3 ml) and finally CrO3 (44 g, 0.44 mol) were added in small portions, at a rate to maintain the temperature of the reaction mixture between 20-30° C. Stirring was continued for 24 hours. Then 200 ml of water and Na2CO3 were added slowly, until the brown color of chromic acid was gone, and the product was extracted with ethyl acetate (3×200 ml). Combined organic layers were washed with water and brine and dried over magnesium sulfate and solvent was removed. The residue was distilled under reduced pressure (110° C., 19 mbar) to give 12.85 g of the desired product.
Workup
- customimmersed in an ice bath
- customequipped with an efficient mechanical stirrer
- extractionthe product was extracted with ethyl acetate (3×200 ml)
- washCombined organic layers were washed with water and brine
- dry with materialdried over magnesium sulfate and solvent
- customwas removed
- distillationThe residue was distilled under reduced pressure (110° C., 19 mbar)
Sources & evidence
- ORD record
- ord-6244dad811874c7ebf8c5fefe6966ca4
- Source dataset
- uspto-grants-2009_03
- Patent number
- US07511038B2
Reaction notes
Loading…