Process for manufacturing substituted triazolinones

Details Process for manufacturing substituted triazolinones Process for manufacturing substituted triazolinones

2000-09-20

2001-04-24

Ambrose, Michael G. (Department: 1626)

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

Organic compounds

Heterocyclic carbon compounds containing a hetero ring...

Reexamination Certificate

active

06222045

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 reaction of an isothiocyanate with an alkanol to produce a thionocarbamate intermediate product; the alkylation of this thionocarbamate intermediate product to produce an amino intermediate product; the reaction of this amino intermediate product with an alkoxycarbonyl or aryloxycarbonyl hydrazine to produce a substituted triazolinone. In this context, the terms “alkanol” and “alkylation” represent generic terms and thus, include the use of alkanols and 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 reaction of a methyl isothiocyanate with methanol, the methylation of the resultant intermediate and the reaction of the intermediate with methyl cabazate to produce a 5-methoxy-4-methyl-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. 5,917,050 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 substituted triazolinones. The process broadly comprises a) reacting an isothiocyanate of the formula (I)
R
1
—N═C═S  (I)
wherein R
1
represents an unsubstituted or substituted alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkylalkyl, arylalkyl or aryl,
with an alkanol of the formula (II)
R
2
—O—H  (II)
wherein R
2
represents an unsubstituted or substituted alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkylalkyl, arylalkyl or aryl,
in the presence of a catalytic amount of base, to produce a thionocarbarnate intermediate product of the following general formula (III)
wherein R
1
and R
2
are as defined above, b) reacting the intermediate product of formula (III) with an alkylating agent of the formula (IV)
R
3
—X  (IV)
 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 base, to produce an imino intermediate product of the formula (V)
wherein R
1
, R
2
and R
3
are as defined above, and c) reacting the intermediate product of formula (V) with a compound of the formula (VI)
H
2
N—NH—CO
2
—R
4
  (VI)
 wherein R
4
represents an alkyl or an aryl, in the presence of a catalytic amount of an acid to produce a product of the formula (VII)
wherein R
1
, R
2
and R
4
are each as defined above, and d) reacting the intermediate product of formula (VII) with a catalytic amount of a base to produce a final product of the formula (VIII)
 wherein R
1
and R
2
are each as defined above.
DETAILED DESCRIPTION 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 the context of the invention, the terms “alkanol” and “alkylation” represent generic terms and thus, include the use of alkanols and 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.
The process of the present invention includes the step of reacting an isothiocyanate of the formula (I)
R
1
—N═C═S  (I)
wherein
R
1
represents an unsubstituted or substituted alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkylalkyl, arylalkyl or aryl,
with an alkanol of the formula (II)
R
2
—O—H  (II)
wherein
R
2
represents an unsubstituted or substituted alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkylalkyl, arylalkyl or aryl,
in the presence of a catalytic amount of base, to produce a thionocarbamate intermediate product of the formula (III)
wherein R
1
and R
2
are as defined above.
The intermediate product of the general formula (III) is then reacted with an alkylating agent of the following general formula (IV)
R
3
—X  (IV)
wherein
X represents a halogen, —O—SO
2
—O—R
3
, or —O—CO—O—R
3
,
R
3
represents an unsubstituted or substituted alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkylalkyl, aryl or arylalkyl,
in the presence of a base, to produce an imino intermediate product of the following general formula (V)
wherein
R
1
, R
2
and R
3
are as defined above.
The intermediate product of the formula (V) is then reacted with an alkoxycarbonyl or aryloxycarbonyl compound of the formula (VI)
H
2
N—NH—CO
2
—R
4
  (VI)
wherein R
4
represents an alkyl or an aryl,
in the presence of a catalytic amount of an acid to produce a product of the formula (VII)
wherein R
1
, R
2
and R
4
are each as defined above.
The intermediate product of formula (VII) is then reacted with a catalytic amount of a base to produce a final product of the formula (VIII)
wherein R
1
and R
2
are each as defined above.
In a preferred embodiment of the invention,
R
1
and R
2
each 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,
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, and
R
4
represents an alkyl having up to 6 carbon atoms, and each of which is unsubstituted or substituted by cyano, halogen or C
1
-C
4
-alkoxy, or
represents an aryl group having 6 or 10 carbon atoms, each of which is unsubstituted or substituted by c

Affiliated with

Also associated with

Rating

Process for manufacturing substituted triazolinones does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Process for manufacturing substituted triazolinones, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for manufacturing substituted triazolinones will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2455539