Bromine → Methyl 4-bromo-5-chlorothiophene-2-carboxylate

HRID 2047345Notes

Reaction equation

HRID 2047345 reaction equation
[Cl:1][C:2]1[S:6][C:5]([C:7]([O:9][CH3:10])=[O:8])=[CH:4][CH:3]=1.[Cl-].[Cl-].[Cl-].[Al+3].[Br:15]Br>C(Cl)(Cl)Cl>[Br:15][C:3]1[CH:4]=[C:5]([C:7]([O:9][CH3:10])=[O:8])[S:6][C:2]=1[Cl:1]

Participants

5

Reactant 3

HCID 24408BromineHCID 589473Methyl 5-chlorothiophene-2-carboxylateHCID 6451240Aluminum(III) Chloride

Product 1

HCID 57826388Methyl 4-bromo-5-chlorothiophene-2-carboxylateYield 71.2%

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent

Conditions

Temperature
25 °C

Procedure

To a solution of methyl 5-chloro-2-thiophenecarboxylate (7 g, 39.6 mmol) and aluminum trichloride (7.93 g, 59.4 mmol) in chloroform (79 ml) at 25° C. was added bromine (2.86 ml, 55.5 mmol). The resulting solution stirred at 25° C. for 2 h. Ice chips were added to quench and the solution was partitioned between H2O-DCM. The aqueous phase was washed several times with DCM and the combined organic fractions were dried over Na2SO4, concentrated and purified via column chromatography (silica, 5% EtOAc in hexanes) affording methyl 4-bromo-5-chloro-2-thiophenecarboxylate (7.2 g, 28.2 mmol, 71.1% yield) as a white solid; LCMS (ES) m/z=255, 257 (M, M+2)+.

Workup

  1. additionIce chips were added
  2. customto quench
  3. customthe solution was partitioned between H2O-DCM
  4. washThe aqueous phase was washed several times with DCM
  5. dry with materialthe combined organic fractions were dried over Na2SO4
  6. concentrationconcentrated
  7. custompurified via column chromatography (silica, 5% EtOAc in hexanes)

Sources & evidence

ORD record
ord-2ab8005069624a2aaa575a5fd0f499b6
Source dataset
uspto-grants-2013_11
Patent number
US08592475B2

Reaction notes

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