Process for the preparation of 3, 4-alkylenedioxythiophene-2,5-dicarboxylic acid derivatives
AssigneeBayer Aktiengesellschaft
InventorFriedrich Jonas
Life of this patent
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Abstract
A process for the preparation of 3,4-alkylenedioxythiophene-2,5-dicarboxylic acid derivatives of the general formulae IV and V 1 characterized in that at least 2 steps in accordance with formula scheme 1, in which R1, R2, R3 and R4 are identical or different and are a linear or branched, optionally substituted alkyl radical having 1 to 20 carbon atoms, A is lithium, sodium or potassium, and Hal is fluorine, chlorine, bromine or iodine, are carried out without isolation of the intermediates, gives the target products in high purity and yield. 2
Claims5
Process for the preparation of 3,4-alkylenedioxythiophene-2,5-dicarboxylic acid derivatives of the general formulae IV and V
- 4
- characterized in that at least 2 steps in accordance with formula scheme 1, in which R1, R2, R3 and R4 are identical or different and are a linear or branched, optionally substituted alkyl radical having 1 to 20 carbon atoms, A is lithium, sodium or potassium, and Hal is fluorine, chlorine, bromine or iodine, are carried out without isolation of the intermediates.
- R1OOC—CH2—S—CH2—COOR1+R2OOC—COOR2
- 5
Dependencies are inferred from the claim text.