Thiophene derivatives
AssigneeHoffmann-La Roche Inc.
InventorsOtto Hromatka, Dieter Binder
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Abstract
The invention relates to sulphothiophene-carboxylic acids of the following formula ##STR1## wherein A together with the two carbon atoms to which it is attached forms the group ##STR2## and the broken line represents the double bond present in group (a), R.sub.3 and R.sub.4 each represent a hydrogen atom or a lower alkyl group; and the halides and lower alkyl esters thereof.
Claims3
Sulphothiophene-carboxylic acids of the general formulae ##STR12## Wherein A together with the two carbon atoms to which it is attached forms the group ##STR13## and the broken line represents the double bond present in group (a), R.sub.3 and R.sub.4 each represent a hydrogen atom or a lower alkyl group.
3-Sulphothiophene-2-carboxylic acid.
4-sulphothiophene-3-carboxylic acid.
Dependencies are inferred from the claim text.