Preparation of mono-N-sulphonylated diamines
View Patent ↗The present invention relates to a process for preparing mono-N-sulphonylated diamines by reacting diamines with sulphonyl halides in the presence of water, base and organic solvents.
1. Process for preparing compounds of the formula (I),
where
R 1 and R 2 are each independently C 1 -C 20 -alkyl, C 4 -C 15 -aryl or C 5 -C 16 -arylalkyl, or R 1 and R 2 together are a straight-chain or branched C 3 -C 12 -alkylene radical arid
R 3 is C 1 -C 20 -alkyl, C 1 -C 20 -fluoroalkyl or C 4 -C 15 -aryl,
comprising reacting
diamines of the formula (II)
where
R 1 , R 2 and R 3 are as defined under formula (I)
in the presence of water and
in the presence of organic solvent and
in the presence of a base comprising alkali metal, alkaline earth metal hydroxide, or carbonate,
with sulphonyl halides of the formula (III)
R 3 SO 2 X (III)
where
X is fluorine, chlorine, bromine or iodine and
R 3 is as defined under formula (I).
2. Process according to claim 1 , characterized in that R 1 and R 2 are identical and are each phenyl or are together straight-chain C 3 -C 8 -alkylene.
3. Process according to claim 1 , characterized in that R 3 is C 1 -C 4 -alkyl, C 1 -C 4 -fluoroalkyl, phenyl or naphthyl, each of which is optionally further substituted by no, one, two, three, four or five radicals which are selected from the group of C 1 -C 4 -alkyl, C 1 -C 4 -alkoxy, C 1 -C 4 -fluoroalkyl, fluorine and chlorine.
4. Process according to claim 1 , characterized in that X is fluorine or chlorine.
5. Process according to claim 1 , characterized in that chiral compounds of the formula (II) are used which have an optical purity of 80% ee or more.
6. Process according to claim 1 , characterized in that the organic solvent used is selected from the group consisting of an amide, an optionally halogenated aliphatic or aromatic solvent having up to 16 carbon atoms, a nitrile, a sulphoxide or a mixture thereof.
7. Process according to claim 1 , characterized in that the organic solvent used is carbon tetrachloride, chloroform, dichloromethane or chlorobenzene.
8. Process according to one claim 1 , characterized in that the volume ratio of water to organic solvent is 20:1 to 1:20.
9. Process according to claim 1 , characterized in that the reaction mixture forms two liquid phases and the aqueous phase has a pH at 25° C. of 8 or more.
10. Process according to claim 1 , characterized in that the molar ratio of compounds of the formula (II) to compounds of the formula (III) is 0.5 to 1.3.
11. Process according to claim 1 , further characterized in that the products are isolated from the reaction solution, by conversion into the hydrohalide, crystallization or precipitation of the hydrohalide and release of the compound of the formula (I) from the hydrohalide using base.