Process for the manufacture of substituted triazolinones

Details Process for the manufacture of substituted triazolinones Process for the manufacture of substituted triazolinones

1999-12-27

2001-03-06

Stockton, Laura L. (Department: 1626)

Organic compounds -- part of the class 532-570 series

Organic compounds

Heterocyclic carbon compounds containing a hetero ring...

Reexamination Certificate

active

06197971

ABSTRACT:

TECHNICAL FIELD OF THE INVENTION
The present invention relates to a process for manufacturing substituted triazolinones, which are intermediates in the preparation of herbicidally active compounds. In particular, this invention relates to the alkylation of a non-alkylated triazolinone intermediate product, wherein the improvement comprises conducting the alkylation reaction under pH controlled conditions. In this context the term “alkylation” represents a generic term and thus, includes the use of alkylating agents having an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, a cycloalkylalkyl group, an aryl group or an arylalkyl group.
In a preferred embodiment, the invention relates to the preparation of a 5-alkoxy(or aryloxy)-2,4-dihydro-3H-1,2,4-triazol-3-one, and the alkylation of this non-alkylated triazolinone intermediate product to produce a 5-alkoxy(or aryloxy)-4-alkyl-2,4-dihydro-3H-1,2,4-triazol-3-one.
BACKGROUND OF THE INVENTION
Triazolinones are well known in the art, as are processes for their preparation and use as herbicides. U.S. Pat. No. 5,708,183 describes a process for the preparation of substituted triazolinones by reacting triazolinethiones with methyl iodide, in the presence of an acid binding agent, and then heating the alkylthiodiazole derivative with hydrogen peroxide in the presence of acetic acid. U.S. Pat. No. 5,912,354 discloses a process for the preparation of substituted aminotriazolinones, which includes reacting an oxadiazolinone with hydrazine hydrate in the absence of a solvent. U.S. Pat. No. 5,917,050 describes a process for the preparation of alkoxytriazolinones by reacting thioimidodicarboxylic diesters with hydrazine, hydrazine hydrate or an acid adduct of hydrazine, in the presence of a diluent and a basic reaction auxiliary.
Further, U.S. Pat. Nos. 5,606,070; 5,599,945; and 5,594,148; each describes a process for the preparation of alkoxytriazolinones which includes reacting iminothiocarbonic diesters with carbazinic esters, and then subjecting the resultant semicarbazide derivatives to a cyclizing condensation reaction.
However, these prior art processes produce triazolinones in unsatisfactory yield and purity. Thus, there is a need in the art for a process to manufacture substituted triazolinones in high yield and purity.
BRIEF SUMMARY OF INVENTION
The present invention is related to a process for the preparation of a substituted triazolinone. The process includes the reaction of a thionocarbamate of the following general formula (I)
wherein
R
1
represents an unsubstituted or substituted alkyl, arylalkyl or aryl, and
R
2
represents an unsubstituted or substituted alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkylalkyl, aryl or arylalkyl,
with hydrazine, hydrazine hydrate or an acid adduct of hydrazine, to produce a triazolinone intermediate product of the following general formula (II)
wherein
R
2
is as defined above.
The intermediate product of the general formula (II) is then reacted under pH controlled reaction conditions with an alkylating agent of the following general formula (III)
R
3
—X  (III)
wherein
X represents a halogen, —O—SO
2
—O—R
3
, or —O—CO—O—R
3
, and
R
3
represents an unsubstituted or substituted alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkylalkyl, aryl or arylalkyl, in the presence of a solvent and a base, to produce a substituted triazolinone of the following general formula (IV)
wherein
R
2
and R
3
are as defined above.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is related to a process for the preparation of a substituted triazolinone by the alkylation of a non-alkylated triazolinone intermediate product. In this context, the term “alkylation” is used as a generic term and thus, expressly includes the definition of R
3
provided below. The process includes the reaction of a thionocarbamate of the following general formula (I)
wherein
R
1
represents an unsubstituted or substituted alkyl, arylalkyl or aryl, and
R
2
represents an unsubstituted or substituted alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkylalkyl, aryl or arylalkyl, with hydrazine, hydrazine hydrate or an acid adduct of hydrazine, to produce a triazolinone intermediate product of the following general formula (II)
wherein
R
2
is as defined above.
The intermediate product of the general formula (II) is then reacted under pH controlled reaction conditions with an alkylating agent of the following general formula (III)
R
3
—X  (III)
wherein
X represents a halogen, —O—SO
2
—O—R
3
, or —O—CO—O—R
3
, and
R
3
represents an unsubstituted or substituted alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkylalkyl, aryl or arylalkyl, in the presence of a solvent and a base, to produce a substituted triazolinone of the following general formula (IV)
wherein
R
2
and R
3
are as defined above.
In a preferred embodiment of the invention,
R
1
represents an alkyl group having 1 to 4 carbon atoms, a benzyl group or a phenyl group, and
R
2
represents an alkyl group, an alkenyl group or an alkynyl group having in each case up to 6 carbon atoms, and each of which is unsubstituted or substituted by cyano, halogen or C
1
-C
4
-alkoxy, or
represents a cycloalkyl group having 3 to 6 carbon atoms or a cycloalkylalkyl group having 3 to 6 carbon atoms in the cycloalkyl moiety and 1 to 4 carbon atoms in the alkyl moiety, each of which is unsubstituted or substituted by halogen or C
1
-C
4
-alkyl, or
represents an aryl group having 6 or 10 carbon atoms or an arylalkyl group having 6 or 10 carbon atoms in the aryl moiety and 1 to 4 carbon atoms in the alkyl moiety, each of which is unsubstituted or substituted by carboxyl, nitro, cyano, halogen, C
1
-C
4
-alkyl, C
1
-C
4
-halogenoalkyl, C
1
-C
4
-alkoxy, C
1
-C
4
-halogenoalkoxy or C
1
-C
4
-alkoxy-carbonyl, and
R
3
represents an alkyl, alkenyl or alkynyl, each of which has up to 6 carbon atoms and each of which is unsubstituted or substituted by cyano, halogen or C
1
-C
4
-alkoxy, or
represents a cycloalkyl having 3 to 6 carbon atoms or a cycloalkylalkyl having 3 to 6 carbon atoms in the cycloalkyl moiety and 1 to 4 carbon atoms in the alkyl moiety, each of which is unsubstituted or substituted by halogen or C
1
-C
4
-alkyl, or
represents an aryl having 6 to 10 carbon atoms or an arylalkyl having 6 or 10 carbon atoms in the aryl moiety and 1 to 4 carbon atoms in the alkyl moiety, each of which is unsubstituted or substituted by carboxyl, cyano, nitro, halogen, C
1
-C
4
-alkyl, C
1
-C
4
-halogenoalkyl, C
1
-C
4
-alkoxy, C
1
-C
4
-halogenoalkoxy or C
1
-C
4
-alkoxy-carbonyl.
More preferably,
R
2
represents methyl, ethyl, n- or i-propyl, n-, i-, s-, or t-butyl, each of which is unsubstituted or substituted by cyano, fluorine, chlorine or bromine, methoxy or ethoxy, or
represents propenyl, butenyl, propinyl or butinyl, each of which is unsubstituted or substituted by cyano, fluorine, chlorine or bromine, or
represents cyclopropyl or cyclopropylmethyl, each of which is unsubstituted or substituted by fluorine, chlorine, bromine, methyl or ethyl, or
represents phenyl or benzyl, each of which is unsubstituted or substituted by cyano, fluorine, chlorine, bromine, methyl, ethyl, trifluoromethyl, methoxy, ethoxy, difluoromethoxy, trifluoromethoxy, methoxycarbonyl or ethoxycarbonyl, and
R
3
represents methyl, ethyl, n- or i-propyl or n-, i-, s- or t-butyl, each of which is unsubstituted or substituted by cyano, fluorine, chlorine or bromine, methoxy or ethoxy, or
represents propenyl, butenyl, propinyl or butinyl, each of which is unsubstituted or substituted by cyano, fluorine, chlorine or bromine, or
represents cyclopropyl, cyclobutyl or cyclopropylmethyl, each of which unsubstituted or substituted by fluorine, chlorine, bromine, methyl or ethyl, or
represents phenyl or benzyl, each of which is unsubstituted or substituted by cyano, fluorine, chlorine, bromine, methyl, ethyl, trifluoromethyl, methoxy, ethoxy, difluoromethoxy, trifluoromethoxy, methoxycarbonyl or ethoxycarbonyl.
Most preferably,
R
1
and R
2
each represents methyl, n- or i-propyl, and
R
3
represents me

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