Method for producing enaminocarbonyl compounds
View Patent ↗The present invention relates to a process for the preparation of enaminocarbonyl compounds of the formula (I) where compounds of the formula (II) are reacted in the presence of a Brønsted acid to give compounds of the formula (I), and A, R1 and Z are as defined in the description, and also corresponding starting compounds which are used in the process according to the invention.
1. A process for preparing a compound of formula (I)
comprising reacting a compound of formula (II)
in the presence of a Brønsted acid to give a compound of formula (I),
where
R 1 is hydrogen, alkyl, or haloalkyl;
Z is hydrogen, alkali metal or alkaline earth metal; and
A is pyrid-2-yl or pyrid-4-yl or is pyrid-3-yl which is optionally substituted in position 6 by fluorine, chlorine, bromine, methyl, trifluoromethyl or trifluoromethoxy.
2. A process according to claim 1 , wherein the Brønsted acid is selected from the group consisting of H 3 PO 4 , H 2 SO 4 , HCl, HBr, HF, KHSO 4 , trifluoroacetic acid, acetic acid, methanesulphonic acid and p-toluenesulphonic acid.
3. A process according to claim 1 , where
R 1 is hydrogen, C 1-12 -alkyl, or C 1-12 -haloalkyl.
4. A process according to claim 1 , where
A is 6-fluoropyrid-3-yl, 6-chloropyrid-3-yl, 5-fluoro-6-chloropyrid-3-yl, 5,6-dichloropyrid-3-yl, 5-bromo-6-chloropyrid-3-yl, 5-fluoro-6-bromopyrid-3-yl, 5-chloro-6-bromopyrid-3-yl, 5,6-dibromopyrid-3-yl, 5-methyl-6-chloropyrid-3-yl, 5-chloro-6-iodopyrid-3-yl or 5-difluoromethyl-6-chloropyrid-3-yl;
R 1 is methyl, ethyl, propyl, 2-fluoroethyl, or 2,2-difluoroethyl; and
Z is sodium, potassium or hydrogen.
5. A process according to claim 1 , where
A is 6-chloropyrid-3-yl, 6-bromopyrid-3-yl, 5-fluoro-6-chloropyrid-3-yl or 5-fluoro-6-bromopyrid-3-yl and
R 1 is methyl, ethyl, n-propyl, 2-fluoroethyl or 2,2-difluoroethyl; and
Z is sodium or hydrogen.
6. A process according to claim 1 , wherein the reacting is carried out in at least one solvent which is selected from the group consisting of dioxane, butyronitrile, propionitrile, acetonitrile, DME, toluene, methyl-THF, dichlorobenzene, chlorobenzene, n-heptane, isobutanol, n-butanol, ethanol, methyl tert-butyl ether, and isopropyl ethyl ether.
7. A process according to claim 1 , wherein the reacting is carried out at a temperature from 20° C. to 150° C.
8. A process according to claim 1 , wherein the compound of formula (I) is 4-[[(6-chloropyridin-3-yl)methyl](2,2-difluoroethyl)amino]furan-2(5H)-one.