Claims
- 1. A sulfopyridone of the formula V ##STR101## where X is C.sub.2 -C.sub.8 -alkylene with or without interruption by an ether oxygen atom, in the form of the free acid or its salts.
- 2. The sulfopyridone of claim 1, wherein X is C.sub.2 -alkylene.
- 3. The sulfopyridone of claim 1, wherein X is C.sub.3 -alkylene.
- 4. A process for preparing the sulfopyridone of claim 1, which comprises reacting a cyanopyridone of the formula VI ##STR102## where X is as defined in claim 1, with concentrated sulfuric acid at from 80.degree. to 130.degree. C.
- 5. The process of claim 4, wherein the reaction is carried out at from 90.degree. to 125.degree. C.
- 6. The process of claim 4, wherein 2 to 2.5 parts by weight of concentrated sulfuric acid are used per part by weight of cyanopyridone (VI).
- 7. The process of claim 4, wherein the concentrated sulfuric acid contains sulfur trioxide in amounts to yield 2 to 5% strength by weight oleum.
Priority Claims (1)
Number |
Date |
Country |
Kind |
44 16 266.9 |
May 1994 |
DEX |
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Parent Case Info
This is a Division of application Ser. No. 08/432,815 filed on May 2, 1995, now U.S. Pat. No. 5,554,737.
Foreign Referenced Citations (2)
Number |
Date |
Country |
0226541 |
Jun 1987 |
EPX |
45-29661 |
Sep 1970 |
JPX |
Divisions (1)
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Number |
Date |
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Parent |
432815 |
May 1995 |
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