Production method of heterocyclic mercapto compound
View Patent ↗A method of the invention industrially produces heterocyclic mercapto compounds useful as raw materials or intermediates in the synthesis of medicaments or pesticides, or as permanent wave agent, with a high yield and high productivity using easily available starting materials. A heterocyclic mercapto compound represented by Formula (1) (wherein X represents any structure of —O—, —S—, —NH—, and —NR 1 —; R 1 represents any of an alkyl group, alkoxy group and alkoxyalkyl group each having 1 to 6 carbon atoms; Y represents an oxygen atom, a sulfur atom or —NR 2 —; R 2 represents a hydrogen atom or alkyl group having 1 to 6 carbon atoms; and Z 1 represents a divalent organic residue having at least one mercapto group) is produced by reacting a metal sulfide or a metal hydrosulfide with a compound represented by Formula (2) (wherein X and Y are as defined in Formula (1); and Z 2 represents a divalent organic residue having at least one halogen group) in the presence of a solvent at a pH of 7.0 to 11.0.
1. A method for producing a mercapto lactone, mercapto thiolactone or mercapto lactam represented by Formula (1):
wherein X represents any structure of —O—, —S—, —NH—, and —NR 1 —; R 1 represents any of an alkyl group, alkoxy group and alkoxyalkyl group each having 1 to 6 carbon atoms; and Z 1 represents an alkylene group having one mercapto group and the mercapto group is directly bound to the carbon atom adjacent to the carbonyl carbon in the compound represented by Formula (1),
the method comprising reacting a metal sulfide or a metal hydrosulfide with a compound represented by Formula (2) in the presence of a solvent at a pH of 7.0 to 11.0:
wherein X is as defined in Formula (1); and Z 2 represents an alkylene group having one halogen group and the halogen group is directly bound to the carbon atom adjacent to the carbonyl carbon in the compound represented by Formula (2).
2. The method for producing a mercapto lactone, mercapto thiolactone or mercapto lactam according to claim 1 , wherein the compound represented by Formula (1) is selected from the group consisting of 2-mercapto-4-butyrolactone (2-mercapto-4-butanolide), 2-mercapto-4-methyl-4-butyrolactone, 2-mercapto-4-ethyl-4-butyrolactone, 2-mercapto-4-butyrothiolactone, 2-mercapto-4-butyrolactam, N-methoxy-2-mercapto-4-butyrolactam, N-ethoxy-2-mercapto-4-butyrolactam, N-methyl-2-mercapto-4-butyrolactam, N-ethyl-2-mercapto-4-butyrolactam, N-(2-methoxy)ethyl-2-mercapto-4-butyrolactam, N-(2-ethoxy)ethyl-2-mercapto-4-butyrolactam, 2-mercapto-5-valerolactone, 2-mercapto-5-valerolactam, N-methyl-2-mercapto-5-valerolactam, N-ethyl-2-mercapto-5-valerolactam, N-(2-methoxy)ethyl-2-mercapto-5-valerolactam, N-(2-ethoxy)ethyl-2-mercapto-5-valerolactam, and 2-mercapto-6-hexanolactam.
3. The method for producing a mercapto lactone, mercapto thiolactone or mercapto lactam according to claim 1 , wherein the metal sulfide is an alkali metal sulfide, an alkaline earth metal sulfide or a mixture thereof.
4. The method for producing a mercapto lactone, mercapto thiolactone or mercapto lactam according to claim 1 , wherein the metal sulfide is at least one compound selected from the group consisting of sodium sulfide, potassium sulfide, calcium sulfide and magnesium sulfide.
5. The method for producing a mercapto lactone, mercapto thiolactone or mercapto lactam according to claim 1 , wherein the metal hydrosulfide is sodium hydrosulfide or potassium hydrosulfide.
6. The method for producing a mercapto lactone, mercapto thiolactone or mercapto lactam according to claim 1 , wherein the solvent is a mixed solvent of water and an organic solvent in which the water:organic solvent weight ratio is 1:0.1-10.
7. The method for producing a mercapto lactone, mercapto thiolactone or mercapto lactam according to claim 6 , wherein the organic solvent is one or more solvents selected from the group consisting of methanol, N-methylpyrrolidone, acetone, 1,4-dioxane, 1,2-dimethoxyethane and N,N-dimethylformamide.
8. The method for producing a mercapto lactone, mercapto thiolactone or mercapto lactam according to claim 1 , wherein the pH is maintained in the aforementioned range by adding an inorganic acid or an inorganic alkali to the reaction solution from the start of the reaction to the completion of the reaction.
9. The method for producing a mercapto lactone, mercapto thiolactone or mercapto lactam according to claim 1 , wherein the reaction is performed at not more than 40° C.
10. The method for producing a mercapto lactone, mercapto thiolactone or mercapto lactam according to claim 1 , wherein the reaction is performed by dissolving or dispersing the metal sulfide or the metal hydrosulfide in the solvent and adding the compound represented by Formula (2) to the resultant solution or slurry while controlling the temperature of the solution or slurry in the range of −20 to 40° C.
11. The method for producing a mercapto lactone, mercapto thiolactone or mercapto lactam according to claim 1 , wherein the reaction is performed by dissolving or dispersing the metal sulfide or the metal hydrosulfide in the solvent; adjusting the pH of the resultant solution or slurry in the range of 7.5 to 11.0; and adding the compound represented by Formula (2) to the solution or slurry.
12. The method for producing a mercapto lactone, mercapto thiolactone or mercapto lactam according to claim 11 , wherein the pH of the solution or slurry of the metal sulfide or the metal hydrosulfide is achieved by adding an inorganic acid to the solution or slurry while controlling the temperature of the solution or slurry at not more than 40° C.
13. The method for producing a mercapto lactone, mercapto thiolactone or mercapto lactam according to claim 1 , wherein the equivalent ratio of the compound represented by Formula (2) to the metal sulfide or the metal hydrosulfide is 1:0.8-5.0.
14. The method for producing a mercapto lactone, mercapto thiolactone or mercapto lactam according to claim 1 , further comprising adjusting the pH of the reaction solution in the range of 2.0 to 6.0 after the completion of the reaction.
15. The method for producing a mercapto lactone, mercapto thiolactone or mercapto lactam according to claim 14 , wherein the pH of the reaction solution after the reaction is achieved by adding an inorganic acid thereto after the completion of the reaction.