Synthesis of a thiosulfonic acid by a step of periodate mediated oxidative coupling of a thiosulfonic acid with an aniline
The present invention pertains generally to the field of chemical synthesis, and more particularly to methods for the chemical synthesis of a thiosulfonic acid of Formula (1) by a step of periodate mediated oxidative coupling of a thiosulfonic acid of Formula (2) with an aniline of Formula (3), as described herein. The present invention also relates to such methods which incorporate one or more additional (subsequent and/or preceding) steps, for example, to prepare compounds of Formula (5) from compounds of Formula (1); to prepare compounds of Formula (6) from compounds of Formula (5); and to prepare compounds of Formula (2) from compounds of Formula (4), as described herein.
1. A method of chemical synthesis of a compound of Formula (1):
comprising a step of periodate mediated oxidative coupling, in which a compound of Formula (2):
is reacted with a compound of Formula (3):
and a periodate oxidising agent;
to form said compound of Formula (1);
wherein:
—R 1A1 is independently C 1-4 alkyl; C 2-4 alkenyl; halogenated C 1-4 alkyl; C 5-10 aryl; halogenated C 5-10 aryl; C 5-10 aryl-C 1-4 alkyl; or halogenated C 5-10 aryl-C 1-4 alkyl;
—R 1A2 is independently C 1-4 alkyl; C 2-4 alkenyl; halogenated C 1-4 alkyl; C 5-10 aryl; halogenated C 5-10 aryl; C 5-10 aryl-C 1-4 alkyl; or halogenated C 5-10 aryl-C 1-4 alkyl;
—R 1B1 is independently C 1-4 alkyl; C 2-4 alkenyl; halogenated C 1-4 alkyl; C 5-10 aryl; halogenated C 5-10 aryl; C 5-10 aryl-C 1-4 alkyl; or halogenated C 5-10 aryl-C 1-4 alkyl;
—R 1B2 is independently C 1-4 alkyl; C 2-4 alkenyl; halogenated C 1-4 alkyl; C 5-10 aryl; halogenated C 5-10 aryl; C 5-10 aryl-C 1-4 alkyl; or halogenated C 5-10 aryl-C 1-4 alkyl;
—R 2A is independently —H or —R 3AA ;
—R 2AA is independently C 1-4 alkyl; C 2-4 alkenyl; halogenated C 1-4 alkyl; C 5-10 aryl; halogenated C 5-10 aryl; C 5-10 aryl-C 1-4 alkyl; or halogenated C 5-10 aryl-C 1-4 alkyl;
—R 2B is independently —H or —R 3AA ;
—R 2BB is independently C 1-4 alkyl; C 2-4 alkenyl; halogenated C 1-4 alkyl; C 5-10 aryl; halogenated C 5-10 aryl; C 5-10 aryl-C 1-4 alkyl; or halogenated C 5-10 aryl-C -1- 4 alkyl;
—R 3A is independently —H or —R 3AA ;
—R 3AA is independently C 1-4 alkyl; C 2-4 alkenyl; halogenated C 1-4 alkyl; C 5-10 aryl; halogenated C 5-10 aryl; C 5-10 aryl-C 1-4 alkyl; or halogenated C 5-10 aryl-C 1-4 alkyl;
—R 3B is independently —H or —R 3BB ;
—R 3BB is independently C 1-4 alkyl; C 2-4 alkenyl; halogenated C 1-4 alkyl; C 5-10 aryl; halogenated C 5-10 aryl; C 5-10 aryl-C 1-4 alkyl; or halogenated C 5-10 aryl-C 1-4 alkyl;
—R 4A is independently —H or —R 4AA ;
—R 4AA is independently C 1-4 alkyl; C 2-4 alkenyl; halogenated C 1-4 alkyl; C 5-10 aryl; halogenated C 5-10 aryl; C 5-10 aryl-C 1-4 alkyl; or halogenated C 5-10 aryl-C 1-4 alkyl;
—R 4B is independently —H or —R 4BB ; and
—R 4BB is independently C 1-4 alkyl; C 2-4 alkenyl; halogenated C 1-4 alkyl; C 5-10 aryl; halogenated C 5-10 aryl; C 5-10 aryl-C 1-4 alkyl; or halogenated C 5-10 aryl-C 1-4 alkyl.
2. A method according to claim 1 , wherein each —R 1A1 is independently C 1-4 alkenyl; C 2-4 alkenyl; or halogenated C 1-4 alkyl.
3. A method according to claim 1 , wherein —R 1A2 is independently C 1-4 alkyl; C 2-4 alkenyl; or halogenated C 1-4 alkyl preferably.
4. A method according to claim 1 , wherein —R 1B1 is independently C 1-4 alkenyl; C 2-4 alkentl; or halogenated C 1-4 alkyl.
5. A method according to claim 1 , wherein —R 1B2 is independently C 1-4 alkyl; C 2-4 alkenyl; or halogenated C 1-4 alkyl.
6. A method according to claim 1 , wherein —R 2AA , if present, is independently C 1-4 alkyl; C 2-4 alkenyl; or halogenated C 1-4 alkyl.
7. A method according to claim 1 , wherein —R 2BB , if present, is independently C 1-4 alkyl; C 2-4 alkenyl; or halogenated C 1-4 alkyl.
8. A method according to claim 1 , wherein —R 3AA , if present, is independently C 1-4 alkyl; C 2-4 alkenyl; or halogenated C 1-4 alkyl.
9. A method according to claim 1 , wherein —R 3BB , if present, is independently C 1-4 alkyl; C 2-4 alkenyl; or halogenated C 1-4 alkyl.
10. A method according to claim 1 , wherein —R 4AA , if present, is independently C 1-4 alkyl; C 2-4 alkenyl; or halogenated C 1-4 alkyl.
11. A method according to claim 1 , wherein —R 4BB , if present, is independently C 1-4 alkyl; C 2-4 alkenyl; or halogenated C 1-4 alkyl.
12. A method according to claim 1 , wherein the periodate oxidizing agent is iodine peroxide, periodic acid or a periodate salt.
13. A method according to claim 12 , wherein the periodate oxidizing agent is an alkali metal periodate salt such as a sodium periodate salt.
14. A method according to claim 1 , wherein the ratio, A, of the amount of compound of Formula (2), in equivalents, to the amount of compound of Formula (3), in equivalents, is from about 0.5 to about 3.0.
15. A method according to claims 1 , wherein the ratio, B, of the amount of compound of Formula (2), in equivalents, to the amount of compound of periodate oxidizing agent, in equivalents, is from about 0.5 to about 3.0.
16. A method according to claim 1 , wherein the reaction is carried out in the presence of an acid.
17. A method according to claim 16 , wherein the ratio, C, of the amount of compound of Formula (2), in equivalents, to the amount of H+ provided by the acid, in equivalents, is from about 0.5 to about 3.0.
18. A method according to claim 1 , wherein the reaction is carried out in the presence of water.
19. A method according to claim 1 , wherein the method further comprises a preceding step of:
converting a compound of Formula (4):
to the corresponding compound of Formula (2):
20. A method according to claim 1 , wherein the method further comprises a subsequent step of:
converting the compound of Formula (1):
to the corresponding compound of Formula (5):
wherein X − is one or more anionic counter ions to achieve electrical neutrality.
21. A method according to claim 20 , wherein the method further comprises a subsequent step of:
converting the compound of Formula (5):
to the corresponding compound of Formula (6):
wherein Y − and Z − , taken together, are one or more anionic counter ions to achieve electrical neutrality.