Preparation of 2,2′-di(3,4-ethylenedioxythiophene)s
View Patent ↗The invention relates to a process for preparing compounds of the general formula (I) to novel compounds of this substance class and also to their use as important precursors or for preparing important precursors for π-conjugated polymers.
1. Process for preparing compounds of the general formula (I)
where
A is an optionally substituted C 2 –C 4 -alkylene radical,
R is one or more, identical or different, linear or branched, optionally substuituted C 1 –C 18 -alkyl radical(s), optionally substituted C 5 –C 12 -cycloalkyl radical(s), optionally substituted C 6 –C 14 -aryl radical(s), optionally substituted C 1 –C 4 -hydroxyalkyl radical(s) or one or more hydroxyl radical(s),
x is an integer from 0 to 8,
comprising reacting compounds of the general formula (II)
where
A, R and x are each as defined for the compounds of the general formula (I)
with a dehydrogenating agent.
2. Process according to claim 1 , characterized in that
A is an optionally substituted ethylene radical,
R is one or more, identical or different, linear or branched, optionally substuituted C 1 –C 18 -alkyl radical(s), optionally substituted C 5 –C 12 -cycloalkyl radical(s), optionally substituted C 6 –C 14 -aryl radical(s), optionally substituted C 1 –C 4 -hydroxyalkyl radical(s) or one or more hydroxyl radical(s),
x is an integer from 0 to 4.
3. Process according to claim 1 characterized in that
A is an optionally substituted ethylene radical,
R is methyl, ethyl, n-propyl, n-butyl, n-hexyl, n-octyl, n-decyl, n-dodecyl, n-tetradecyl or hydroxymethyl,
x is 0 or 1.
4. Process according to claim 1 for preparing the compound of the formula (I-a)
comprising reacting compounds of the formula (II-a)
with a dehydrogenating agent.
5. Process according to claim 1 , characterized in that the dehydrogenating agent is selected from the group of the quinones, sulphur, bromine, N-chloro- or N-bromosuccinimide, sulphuryl-chloride, hydrogen peroxide and iodosobenzene.
6. Process according to claim 1 , characterized in that the dehydrogenating agent is a quinone.
7. Process according to claim 1 characterized in that the dehydrogenating agent is 2,3,5,6-tetrachloro-1,4-benzoquinone (chloranil) or 2,3-dichloro-5,6-dicyano-1,4-benzoquinone.
8. Compounds of the general formula (I)
where
A, R and x are each as defined in claim 1 , excluding the compound of the formula (I-a)
9. A process for preparing electrically conducting or semiconducting compounds and/or electrically conducting or semiconducting polymers comprising providing the compounds according to claim 8 as a precursor.
10. Process for preparing compounds of the general formula (III)
where
A, R and x are each as defined in claim 1 and
Hal is Cl or Br,
excluding the compound of the formula (III-a)
comprising halogenating compounds of the general formula (I)
where
A, R and x are each as defined in claim 1 .
11. Process for preparing neutral or cationic compounds of the general formula (IV)
where
A, R and x are each as defined in claim 1 ,
m is an even integer from 2 to 200 and
in the case that the compounds of the general formula (IV) are cationic, they bear a positive charge from at least one up to at most m+2,
comprising oxidatively polymerizing compounds of the general formula (I)
where
A, R and x are each as defined in claim 1 .