Thionyl Chloride → 6-Bromopyridine-2-carbonyl chloride
Reaction equation
[Br:1][C:2]1[N:7]=[C:6]([C:8]([OH:10])=O)[CH:5]=[CH:4][CH:3]=1.S(Cl)([Cl:13])=O>>[Br:1][C:2]1[N:7]=[C:6]([C:8]([Cl:13])=[O:10])[CH:5]=[CH:4][CH:3]=1Participants
Procedure
4 g of 6-bromopyridine-2-carboxylic acid and 25 g of thionyl chloride are refluxed for 1 hour. The excess thionyl chloride is removed in a vacuum and the residue is distilled on a bulb tube at 110° C. and 0.04 mbar. The 6-bromopyridine-2-carboxylic acid chloride thus obtained is dissolved together with 3.32 g of 4-aminobutyric acid ethyl ester, hydrochloride in 40 ml of dioxane, mixed under ice cooling with 6 g of triethylamine and stirred for 5 hours at room temperature. The reaction mixture is added to water, extracted with diethyl ether, dried (sodium sulfate) and concentrated by evaporation. The residue is distilled on a bulb tube at 170° C. and 0.04 mbar and 3.2 g of 4-(6-bromo-2-pyridylcarbonylamino)-butyric acid ethyl ester is thus obtained as bright yellow oil.
Workup
- customThe excess thionyl chloride is removed in a vacuum
- distillationthe residue is distilled on a bulb tube at 110° C.
Sources & evidence
- ORD record
- ord-2bcba190f5a0485baa058d4c1047b880
- Source dataset
- uspto-grants-1997_03
- Patent number
- US05614634
Reaction notes
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