Claims
- 1. A process for the preparation of 4-amino-3-oxo-2,3,4,5-tetrahydro-1,2,4-triazine derivatives of the formula I ##STR13## wherein R.sub.1 is hydrogen, C.sub.1 -C.sub.12 alkyl, C.sub.3 -C.sub.6 cycloalkyl, C.sub.1 -C.sub.4 alkoxy-C.sub.1 -C.sub.6 alkyl, C.sub.1 -C.sub.2 haloalkyl, phenyl, benzyl, phenethyl, phenpropyl, phenbutyl or phenpentyl, or a phenyl, benzyl, phenethyl, phenpropyl, phenbutyl or phenpentyl radical that is mono- or di-substituted by halogen, C.sub.1 -C.sub.5 alkyl, C.sub.1 -C.sub.2 haloalkyl, methoxy and/or ethoxy; R.sub.2 is hydrogen, C.sub.1 -C.sub.6 alkyl or C.sub.3 -C.sub.6 cycloalkyl, or is phenyl that is unsubstituted or substituted by C.sub.1 -C.sub.12 alkyl, halogen or by C.sub.1 -C.sub.12 haloalkyl, or R.sub.1 and R.sub.2 together form a saturated or unsaturated 3- to 7-membered carbocycle, and R.sub.3 is hydrogen or C.sub.1 -C.sub.6 alkyl, by the solvolysis of compounds of the formula II ##STR14## wherein R.sub.4 is H, C.sub.1 -C.sub.4 -alkyl, C.sub.3 -C.sub.6 -cycloalkyl, C.sub.1 -C.sub.4 -alkyl substituted by 1 to 9 chlorine atoms, C.sub.1 -C.sub.3 -alkoxy, C.sub.1 -C.sub.3 -alkylthio, phenyl, pyridyl, or phenyl or pyridyl which is substituted with 1 to 3 substituents selected from the group of halogen, methyl, ethyl, methoxy, methylthio or nitro,
- in the presence of gaseous hydrogen chloride in an alcoholic medium.
- 2. A process according to claim 1, wherein R.sub.1 is methyl or ethyl.
- 3. A process according to claim 1, wherein R.sub.4 is H or C.sub.1 -C.sub.4 -alkyl.
- 4. A process according to claim 1, wherein the alcoholic medium consists of one or more primary, secondary or tertiary alcohols.
- 5. A process according to claim 4, wherein the alcoholic medium consists of methanol, ethanol, n-propanol, isopropanol, n-butanol, n-pentanol or a mixture of these.
- 6. A process according to claim 1, wherein the water content of the reaction medium is between 0 and 5 weight-% with respect to the acetyltriazinone of formula II.
- 7. A process according to claim 6, wherein the reaction is carried out under anhydrous conditions.
- 8. A process according to claim 1, wherein the reaction is conducted at a temperature between 0.degree. C. and the boiling point of the solvent used.
Parent Case Info
This is a division of Ser. No. 08/315,802, filed Sep. 30, 1994, abandoned, which is a division of Ser. No. 08/194,185, filed Feb. 9, 1994, now U.S. Pat. No. 5,384,403, which is a continuation-in-part of Ser. No. 08/040,691, filed Mar. 31, 1993, abandoned.
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
4931439 |
Kristinsson |
Feb 1991 |
|
4996325 |
Kristinsson |
Jun 1990 |
|
5446154 |
Beriger et al. |
Aug 1995 |
|
Foreign Referenced Citations (1)
Number |
Date |
Country |
0433218 |
Jun 1991 |
EPX |
Non-Patent Literature Citations (2)
Entry |
Chem. Abst. 80: 27114d, Jan. 28, 1974. |
Chem. Abst. 83: 113388g, Sep. 29, 1975. |
Divisions (2)
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Number |
Date |
Country |
Parent |
315802 |
Sep 1994 |
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Parent |
194185 |
Feb 1994 |
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Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
40691 |
Mar 1993 |
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