2-Thiophenecarboxylic acid → 5-Chloromethyl-2-thienylcarboxylic acid

HRID 437347

Reaction equation

HRID 437347 reaction equation
[S:1]1[CH:5]=[CH:4][CH:3]=[C:2]1[C:6]([OH:8])=[O:7].[Cl:9][CH2:10]OCCl.[Cl-].[Al+3].[Cl-].[Cl-]>C(Cl)(Cl)Cl>[Cl:9][CH2:10][C:5]1[S:1][C:2]([C:6]([OH:8])=[O:7])=[CH:3][CH:4]=1

Participants

5

Reactant 3

HCID 107002-Thiophenecarboxylic acidHCID 10967Bis(Chloromethyl) EtherHCID 6451240Aluminum(III) Chloride

Product 1

HCID 227677545-Chloromethyl-2-thienylcarboxylic acid

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent

Procedure

2-Thiophenecarboxylic acid is treated in a solution of chloroform with chloromethyl ether in the presence of 0.9 to 2.2 equivalents of aluminum chloride to give 5-chloromethyl-2-thienylcarboxylic acid. Treatment of the obtained acid with excess thionyl chloride at room temperature for about 16 hours yields the acid chloride with is reacted with diazomethane to give the corresponding diazoketone. A methanol solution of the diazoketone is irradiated under nitrogen for about one hour with a high pressure mercury lamp using a Quarz filter. The methyl 5-chloromethyl-2-thienylacetate is obtained upon work up and column chromatography on silica gel. The acetate is hydrolyzed by treatment of a 1:1 mixture of acetic acid and concentrated hydrochloric acid at room temperature overnight to give 5-chloromethyl-2-thienylacetic acid.

Sources & evidence

ORD record
ord-722f3ec218534fcaad4e214fee5e9ed4
Source dataset
uspto-grants-1977_06
Patent number
US04031083

Linked notes

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