Claims
- 1. A method for the synthesis of an amidine sulfonic acid which comprises oxidizing a thiourea with hydrogen peroxide in the presence of Na.sub.2 MoO.sub.4.2H.sub.2 O in the following two stages:
- (i) during addition of the hydrogen peroxide at a temperature of about 0.degree. to 15.degree. C.; and
- (ii) after addition of the hydrogen peroxide at a temperature of above 15.degree. to about 80.degree. C.
- 2. The method of claim 1, wherein the temperature of the addition of the hydrogen peroxide is from about 5.degree. to 10.degree. C.
- 3. The method of claim 1, wherein the maximum temperature of the oxidation is about 60.degree. C.
- 4. The method of claim 1, wherein the maximum temperature of the oxidation is about 40.degree. C.
- 5. A method for the synthesis of an amidine sulfonic acid of the following formula (I) ##STR6## wherein R.sup.1, R.sup.2 and R.sup.3 are independently hydrogen, NH.sub.2, perhaloalkyl, perhaloaryl, NO.sub.2, an organic group or are joined to form an organic group, which comprises oxidizing a thiourea of the following formula (II): ##STR7## with hydrogen peroxide by the addition of Na.sub.2 MoO.sub.4.2H.sub.2 O in the following two stages:
- (i) during addition of the hydrogen peroxide at a temperature of about 0.degree. to 15.degree. C.; and
- (ii) after addition of the hydrogen peroxide at a temperature of above 15.degree. to about 80.degree. C.
- 6. The method of claim 5, wherein the temperature of the addition of the hydrogen peroxide is from about 5.degree. to 10.degree. C.
- 7. The method of claim 5, wherein the maximum temperature of the oxidation is about 60.degree. C.
- 8. The method of claim 5, wherein the maximum temperature of the oxidation is about 40.degree. C.
- 9. The method of claim 5, wherein R.sup.1 is hydrogen.
- 10. The method of claim 5, wherein R.sup.1 and R.sup.2 are hydrogen.
- 11. The method of claim 5, wherein R.sup.1, R.sup.2 and R.sup.3 are hydrogen.
- 12. The method of claim 5, wherein R.sup.1 and R.sup.3 are hydrogen.
- 13. The method of claim 5, wherein R.sup.1 is hydrogen and R.sup.2 and R.sup.3 are joined to form a substituted or unsubstituted dimethylene or trimethylene group.
- 14. The method of claim 5, wherein said organic group is alkyl, substituted alkyl, cyclic alkyl, substituted cyclic alkyl, aryl, substituted aryl, heterocyclic or substituted heterocyclic.
- 15. The method of claim 5, wherein R.sup.1 and R.sup.2 are hydrogen and R.sup.3 is n-propyl.
- 16. The method of claim 5, wherein said amidine sulfonic acid is amidinothiourea.
- 17. The method of claim 5, wherein said amidine sulfonic acid is ethylenethiourea.
- 18. The method of claim 5, wherein said amidine sulfonic acid is 2,6-dichlorophenylthiourea.
- 19. A method for the synthesis of an amidine sulfonic acid which comprises oxidizing a thiourea with hydrogen peroxide in the presence of Na.sub.2 MoO.sub.4.2H.sub.2 O in the following two stages:
- (a) during addition of about 2 equivalents of the hydrogen peroxide at a temperature of about 0.degree. to 15.degree. C.; and
- (b) during addition of the third equivalent of the hydrogen peroxide at a temperature of about 20.degree. to 50.degree. C.
- 20. The method of claim 19, wherein said temperature in stage (b) is about 40.degree. C.
- 21. A method for the synthesis of an amidine sulfonic acid of the following formula (I) ##STR8## wherein R.sup.1, R.sup.2 and R.sup.3 are independently hydrogen, NH.sub.2, perhaloalkyl, perhaloaryl, NO.sub.2, an organic group or are joined to form an organic group, which comprises oxidizing a thiourea of the following formula (II): ##STR9## with hydrogen peroxide by the addition of Na.sub.2 MoO.sub.4.2H.sub.2 O in the following two stages:
- (a) during addition of about 2 equivalents of the hydrogen peroxide at a temperature of about 0.degree. to 15.degree. C.; and
- (b) during addition of the third equivalent of the hydrogen peroxide at a temperature of about 20.degree. to 50.degree. C.
- 22. The method of claim 21, wherein said temperature in stage (b) is about 40.degree. C.
- 23. The method of claim 21, wherein R.sup.1 is hydrogen.
- 24. The method of claim 21, wherein R.sup.1 and R.sup.2 are hydrogen.
- 25. The method of claim 21, wherein R.sup.1, R.sup.2 and R.sup.3 are hydrogen.
- 26. The method of claim 21, wherein R.sup.1 and R.sup.3 are hydrogen.
- 27. The method of claim 21, wherein R.sup.1 is hydrogen and R.sup.2 and R.sup.3 are joined to form a substituted or unsubstituted dimethylene or trimethylene group.
- 28. The method of claim 21, wherein said organic group is alkyl, substituted alkyl, cyclic alkyl, substituted cyclic alkyl, aryl, substituted aryl, heterocyclic or substituted heterocyclic.
- 29. The method of claim 21, wherein R.sup.1 and R.sup.2 are hydrogen and R.sup.3 is n-propyl.
- 30. The method of claim 21, wherein said amidine sulfonic acid is amidinothiourea.
- 31. The method of claim 21, wherein said amidine sulfonic acid is ethylenethiourea.
- 32. The method of claim 21, wherein said amidine sulfonic acid is 2,6-dichlorophenylthiourea.
Parent Case Info
This application is a continuation-in-part of U.S. Ser. No. 711,948 filed Mar. 15, 1985.
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4210658 |
Durant et al. |
Jul 1980 |
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4381395 |
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Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
711948 |
Mar 1985 |
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