Method for the production of 2-fluoroacyl-3-aminoacrylic acid derivatives

1. A process for preparing a 2-fluoroacyl-3-aminoacrylic acid derivative of formula (I)

 in which

R 1 and R 2 are each independently selected from the group consisting of C 1-12 -alkyl, C 3-8 -cycloalkyl, C 2-12 -alkenyl, C 2-12 -alkynyl, C 6-8 -aryl, C 7-19 -arylalkyl and C 7-19 -alkylaryl, each of which may be substituted by one or more groups selected from the group consisting of —R′, —X, —OR′, —SR′, —NR′ 2 , —SiR′ 3 , —COOR′, —(C═O)R′, —CN and —CONR 2 ′, where R′ is hydrogen or a C 1-12 -alkyl group; or

R 1 and R 2 , together with the nitrogen atom to which they are bonded, may form a 5- to 6-membered ring which may optionally contain one or two further heteroatoms selected from the group consisting of O, S and SO 2 , and which may be substituted by one or more groups selected from the group consisting of —R′, —X, —OR′, —SR′, —NR′ 2 , —SiR′ 3 , —COOR′, —(C═O)R′, —CN and —CONR 2 ′, where R′ is hydrogen or a C 1-12 -alkyl group;

Y is selected from the group consisting of (C═O)OR 3 , CN and (C═O)NR 4 R 5 , where R 3 , R 4 and R 5 are each independently selected from the group consisting of C 1-12 -alkyl, C 3-8 -cycloalkyl, C 2-12 -alkenyl, C 2-12 -alkynyl, C 6-8 -aryl, C 7-19 -arylalkyl- and C 7-19 -alkylaryl groups, each of which may be substituted by one or more groups selected from the group consisting of —R′, —X, —OR′, —SR′, —NR′ 2 , —SiR′ 3 , —COOR′, —(C═O)R′, —CN and —CONR 2 ′, where R′ is hydrogen or a C 1-12 -alkyl group; and

X 1 and X 2 are each independently fluorine, chlorine, bromine, hydrogen, C 1-12 -alkyl, C 3-8 -cycloalkyl, C 2-12 -alkenyl, C 2-12 -alkynyl, C 6-8 -aryl, C 7-19 -arylalkyl or C 7-19 -alkylaryl groups, where the aforementioned alkyl, cycloalkyl, alkenyl, alkynyl, aryl, arylalkyl and alkylaryl groups may each be substituted by one or more groups selected from the group consisting of —R′, —X, —OR′, —SR′, —NR′ 2 , —SiR′ 3 , —COOR′, —(C═O)R′, —CN and —CONR 2 ′, where R′ is hydrogen or a C 1-12 -alkyl group;

comprising reacting a fluorinated carboxylic acid of formula (II)

 in which X 1 and X 2 are each as defined above, with a 3-aminoacrylic acid derivative of the formula (III)

 in which R 1 , R 2 and Y are each as defined above, and, in the presence of a base, with an acid halide of the formula (IV)

 in which

R 9 is selected from the group consisting of C 1-12 -alkyl, C 3-8 -cycloalkyl, C 2-12 -alkynyl, C 2-12 -alkynyl, C 6-8 -aryl, C 7-19 -arylalkyl- and C 7-19 -alkylaryl, each of which may be substituted by one or more groups selected from the group consisting of —R′, —X, —OR′, —SR′, —NR′ 2 , —SiR′ 3 , —COOR′, —(C═O)R′, —CN and —CONR 2 ′, where R′ is hydrogen or a C 1-12 -alkyl group; and

Hal is halogen.

2. A process for preparing a 2-fluoroacyl-3-aminoacrylic acid derivative of formula (I)

 in which

R 1 and R 2 are each independently selected from the group consisting of C 1-12 -alkyl radicals, C 5-18 -aryl,

C 7-19 -alkylaryl and C 7-19 -arylalkyl radicals, or

R 1 and R 2 , together with the nitrogen atom to which they are bonded, may form a 5- to 6-membered ring which may optionally contain one or two further heteroatoms selected from the group consisting of O, S and SO 2 ,

Y is selected from the group consisting of (C═O)OR 3 , CN and (C═O)NR 4 R 5 , where R 3 , R 4 and R 5 are each independently selected from the group consisting of C 1-12 -alkyl radicals, C 5-18 -aryl, C 7-19 -alkylaryl and C 7-19 -arylalkyl radicals and

X 1 and X 2 are each independently fluorine, chlorine, bromine, hydrogen, C 1-12 -alkyl radicals, C 1-12 -haloalkyl radicals, C 5-18 -aryl, C 7-19 -alkylaryl or C 7-19 -arylalkyl radicals, comprising reacting a fluorinated carboxylic acid of formula (II)

 in which X 1 and X 2 are each as defined above, with a 3-aminoacrylic acid derivative of the formula (III)

 in which R 1 , R 2 and Y are each as defined above, and, in the presence of a base, with an acid halide of the formula (IV)

 in which

R 9 is C 1-12 alkyl, C 3-8 -cycloalkyl, C 1-12 -haloalkyl, C 5-18 -aryl or C 7-19 -arylalkyl; and

Hal is halogen.

3. The process according to claim 1 or claim 2 , wherein

R 1 and R 2 are each independently selected from the group consisting of methyl, ethyl, n-propyl and isopropyl,

or

R 1 and R 2 together with the nitrogen atom to which they are bonded, form a piperidinyl or pyrrolidinyl ring;

Y is selected from (C═O)OR 3 where R 3 is selected from the group consisting of methyl, ethyl, n-propyl and isopropyl;

X 1 and X 2 are each independently selected from fluorine, chlorine, bromine and hydrogen;

Hal is chlorine or bromine; and

R 9 is selected from C 1-12 -alkyl.

4. The process according to claim 1 or claim 2 , wherein

R 1 and R 2 are each methyl,

Y is (C═O)OC 2 H 5 ;

X 1 is fluorine;

X 2 is hydrogen;

Hal is chlorine and

R 9 is methyl.

5. The process according to claim 1 , wherein the fluorinated carboxylic acid is selected from the group consisting of trifluoroacetic acid, difluoroacetic acid, difluorochloroacetic acid, chlorofluoroacetic acid, 2,3,3,3-tetrafluoropropionic acid, 2,2,3,3-tetrafluoropropionic acid, 2,2-difluoropropionic acid, pentafluoropropionic acid, and 2,3,3,4,4,4-hexafluorobutanecarboxylic acid.

6. The process according to claim 5 , wherein the dialkylaminoacrylic acid derivative is selected from the group consisting of methyl 3-(N,N-dimethylamino)-acrylate, ethyl 3-(N,N-dimethylamino)acrylate, ethyl 3 -(N,N-diethylamino)acrylate, 3-(N,Ndimethylamino)acrylonitrile, N,N-dimethyl-3-(N,N-dimethylamino)acrylamide and N,Ndiethyl-3-(N,N -dimethylamino)acrylamide.

7. The process according to claim 6 , wherein the molar ratio of dialkylaminoacrylic acid derivative to fluorinated carboxylic acid used is 0.5 to 3.

8. The process according to claim 7 , wherein the acid chloride is selected from acetyl chloride, pivaloyl chloride, isovaleroyl chloride and benzoyl chloride.

9. The process according to claim 8 , wherein the molar ratio of acid chloride to the fluorinated carboxylic acid used is 0.5 to 5.

10. The process according to claim 9 , wherein the base is selected from triethylamine, trimethylamine, diisopropylethylamine, tri-n-propylamine, tri-n-butylamine, tri-nhexylamine, tricyclohexylamine, N-methylcyclohexylamine, N-methylpyrrolidine, Nmethylpiperidine, N-ethylpiperidine, N,N-dimethylaniline, N-methylmorpholine, pyridine, 2-,3-, 4-picoline, 2-methyl-5-ethylpyridine, 2,6-lutidine, 2,4,6-collidine, 4-dimethylaminopyridine, quinoline, methylimidazole, ethylimidazole, butylimidazole, quinaldine, N,N,N,N-tetramethylethylenediamine, N,N-dimethyl-1,4-diazacyclohexane, N,Ndiethyl-1,4-diazacyclohexane, 1,8-bis(dimethylamino)naphthalene, diazabicylooctane (DABCO), diazabicyclononane (DBN) and diazabicycloundecane (DBU), sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium hydroxide, sodium carbonate, potassium carbonate, sodium hydrogencarbonate and potassium hydrogencarbonate.