Preparation of isothiazolinones from disulphides and disulphides from isothiazolinones
AssigneeImperial Chemical Industries PLC
InventorsPeter W. Austin, Neville Tyreman
Life of this patent
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Abstract
A compound of the formula ##STR1## in which R.sup.1 and R.sup.2 taken together, and R.sup.3 and R.sup.4 taken together, independently represent a polymethylene chain leaving 3 or 4 carbon atoms, or a polymethylene chain having 3 or 4 carbon atoms substituted by at least one lower alkyl radical having from 1 to 4 carbon atoms and R.sup.5 to R.sup.8 are independently hydrogen, hydrocarbyl or substituted hydrocarbyl. Typically R.sup.1 and R.sup.2 and also R.sup.3 and R.sup.4 complete a trimethylene ring, R.sup.5 and R.sup.7 are each hydrogen and R.sup.6 and R.sup.8 are alkyl such as methyl. The compounds have microbiological activity.
Claims8
A process for making a 4,5-polymethylene-4-isothiazolin-3-one by reacting a compound of general formula I ##STR8## with an oxidising agent in a solvent, wherein R.sup.1 and R.sup.2 taken together, and R.sup.3 and R.sup.4 taken together, independently represent a polymethylene chain having 3 or 4 carbon atoms;
- R.sup.5 and R.sup.7 are both hydrogen;
- and
- R.sup.6 and R.sup.8 are independently hydrogen, hydrocarbyl or substituted hydrocarbyl.
A process for making a compound of general formula IV ##STR9## by reacting a compound of general formula V ##STR10## with an oxidising agent in a solvent wherein R.sup.1 and R.sup.2 taken together represent a polymethylene chain having 3 or 4 carbon atoms;
- and
- R.sup.6 is hydrogen, hydrocarbyl or substituted hydrocarbyl.
A process for making a compound of general formula V ##STR11## by reacting a compound of general formula IV with a reducing agent in a solvent wherein
- R.sup.1 and R.sup.2 taken together represent a polymethylene chain having 3 or 4 carbon atoms or a Polymethylene chain having 3 or 4 carbon atoms substituted by at least one lower alkyl radical having from 1 to 4 carbon atoms;
- and
- R.sup.6 is hydrogen, hydrocarbyl or substituted hydrocarbyl.
Dependencies are inferred from the claim text.