Method for producing unsaturated acid and/or unsaturated acid ester

1. A method for producing an unsaturated acid and/or an unsaturated acid ester, comprising a process A of reacting a compound (1) represented by the following formula (1) at a temperature of 0° C. to 350° C. in the presence of a Brønsted acid catalyst and/or a Lewis acid catalyst, to prepare a compound (2) represented by the following formula (2);

(wherein each of R 1 , R 2 and R 4 independently represents a hydrogen atom, a deuterium atom or an alkyl group which has carbon number of 1 to 3 and may be substituted with a halogen atom and/or a deuterium atom; each of R 3 and R 5 independently represents a hydrogen atom or a deuterium atom; R 6 represents a hydrogen atom, a deuterium atom, or an alkyl group or an aryl group which has carbon number of 1 to 8 and may be substituted with a halogen atom and/or a deuterium atom; and X represents a chlorine atom, a fluorine atom, a bromine atom, or an iodine atom).

2. The production method according to claim 1 , wherein the Brønsted acid catalyst and/or the Lewis acid catalyst is a compound represented by the following general formula (A) or mixture thereof;

M n Y m   (A)

(wherein M represents a hydrogen ion or a cation of metal or metalloid selected from the group consisting of the group 2 elements and the group 4-14 elements in the periodic table; Y represents an anion selected from the group consisting of halide ions, a sulfate ion, a nitrate ion, a carbonate ion, a hydrogencarbonate ion, a sulfide ion, an oxide ion, a hydroxide ion, a alkoxide ions, a phosphate ion, an acetate ion, and a perchlorate ion; and n and m are numbers satisfying the expression, cation M's valence×n=anion Y's valence×m).

3. The production method according to claim 2 , wherein M is a cation of metal selected from the group consisting of zinc, iron and copper, and Y is a fluoride ion, a chloride ion or a bromide ion.

4. The production method according to claim 1 , wherein the Lewis acid catalyst is an activated clay, an acid clay, a zeolite, a heteropoly acid, or an ion exchange resin.

5. The production method according to claim 1 , wherein the Brønsted acid catalyst and/or the Lewis acid catalyst is present in a ratio of 0.001 to 1 mol with respect to 1 mol of the compound (1).

6. The production method according to claim 1 , wherein the process A contains a step of adding an alcohol which has carbon number of 1 to 8 and may be substituted with a halogen atom and/or a deuterium atom, exclusive of the compound (1) represented by formula (1), and/or water.

7. The production method according to claim 1 , further comprising, subsequent to the process A, a process B of preparing a compound (3) represented by the following formula (3) from the product of the process A containing the compound (2);

(wherein R 1 , R 2 , R 4 and R 6 have the same meanings as above, respectively).

8. The production method according to claim 1 , wherein each of R 1 , R 2 , R 4 and R 6 is independently a hydrogen atom, a deuterium atom, or an alkyl group which has carbon number of 1 to 3 and may be substituted with a deuterium atom.

9. The production method according to claim 8 , wherein each of R 1 and R 2 is independently a hydrogen atom or a deuterium atom, and each of R 4 and R 6 is a methyl group which may be substituted with a deuterium atom.

10. The production method according to claim 9 , further comprising, prior to the process A, a process C of reacting an acetone which may be substituted with a deuterium atom, with a halogenoform or a deuterated halogenoform, to prepare the compound (1).