Organic compounds -- part of the class 532-570 series – Organic compounds – Chalcogen in the nitrogen containing substituent
Reexamination Certificate
2000-02-03
2002-03-12
Shah, Mukund J. (Department: 1624)
Organic compounds -- part of the class 532-570 series
Organic compounds
Chalcogen in the nitrogen containing substituent
C544S097000, C544S309000, C544S310000, C544S311000
Reexamination Certificate
active
06355796
ABSTRACT:
BACKGROUND OF THE INVENTION
6-(Perfluoroalkyl)uracil compounds are useful as herbicidal agents and methods for their preparation are known in the art. 6-(Perfluoroalkyl)uracil compounds may be prepared by reacting 2-(N,N-disubstituted)amino-4-(perfluoroalkyl)-1,3-oxazin-6-one compounds with amine compounds.
Bull. Soc. Chem. Belg., 101(4), pages 313-321 (1992) discloses that 2-(N,N-dialkyl)amino-4-(trifluoromethyl)-1,3-oxazin-6-one compounds are prepared by reacting ethyl 3-amino-4,4,4-trifluorocrotonate with phosgene iminium chloride compounds. However, this method is not entirely satisfactory for the preparation of 2-(N,N-disubstituted)amino-4-(perfluoroalkyl)-1,3-oxazin-6-one compounds because the required phosgene iminium chloride compounds are difficult to handle and relatively expensive. Accordingly, a need exists in the art for an improved process for the preparation of 2-(N,N-disubstituted)amino-4-(perfluoroalkyl)-1,3-oxazin-6-one compounds which avoids the use of phosgene iminium chloride compounds.
It is, therefore, an object of the present invention to provide improved processes for the preparation of 2-(N,N-disubstituted)amino-4-(perfluoroalkyl)-1,3-oxazin-6-one compounds.
It is also an object of the present invention to provide intermediate compounds which are useful in the preparation of 2-(N,N-disubstituted)amino-4-(perfluoroalkyl)-1,3-oxazin-6-one compounds.
It is a further object of the present invention to provide an improved process for the preparation of 6-(perfluoroalkyl)uracil compounds.
Other objects and advantages of the present invention will be apparent to those skilled in the art from the description below and the appended claims.
SUMMARY OF THE INVENTION
The present invention provides a new process for the preparation of 2-(N,N-disubstituted)amino-4-(perfluoroalkyl)-1,3-oxazin-6-one compounds having the structural formula I
wherein
Z and Z
1
are each independently C
1
-C
8
alkyl or Z and Z
1
may be taken together with the atom to which they are attached to form a 4- to 7-membered ring wherein ZZ
1
is represented by —(CH
2
)
2
O(CH
2
)
2
— or —(CH
2
)
m
— where m is an integer of 3, 4, 5 or 6; and
n is an integer of 1, 2, 3, 4, 5 or 6,
which comprises:
(a) reacting a &bgr;-amino-&bgr;-(perfluoroalkyl)acrylate compound having the structural formula II
wherein n is as described above, and Z
2
is C
1
-C
6
alkyl or benzyl optionally substituted on the phenyl ring with any combination of from one to three halogen, C
1
-C
4
alkyl or C
1
-C
4
haloalkyl groups, with a base and a carbamoyl chloride compound having the structural formula III
wherein Z and Z
1
are as described above to form a urea compound having the structural formula IV
(b) reacting the formula IV urea with a phosphorous pentahalide or oxalyl halide.
The present invention further provides a process for the preparation of 6-(perfluoroalkyl)uracil compounds having the structural formula V
wherein
n is an integer of 1, 2, 3, 4, 5 or 6;
Z
3
is hydrogen or C
1
-C
6
alkyl; and
Q is a C
1
-C
6
alkyl group or an optionally substituted phenyl, benzyl, heteroaryl or methyleneheteroaryl group,
which process comprises:
(a) reacting a urea compound having the structural formula IV
wherein
Z and Z
1
are each independently C
1
-C
8
alkyl or Z and Z
1
may be taken together with the atom to which they are attached to form a 4- to 7-membered ring wherein
ZZ
1
is represented by —(CH
2
)
2
O(CH
2
)
2
— or —(CH
2
)
m
— where m is an integer of 3, 4, 5 or 6;
Z
2
is C
1
-C
6
alkyl or benzyl optionally substituted on the phenyl ring with any combination of from one to three halogen, C
1
-C
4
alkyl or C
1
-C
4
haloalkyl groups; and
n is as described above, with a phosphorous pentahalide or oxalyl chloride to form a 2-(N,N-disubstituted)amino-4-(perfluoroalkyl)-1,3-oxazin-6-one compound having the structural formula I
(b) reacting the 2-(N,N-disubstituted)amino-4-(perfluoroalkyl)-1,3-oxazin-6-one with an amine compound having the structural formula VI
QNH
2
(VI)
wherein Q is as described above in the presence of an acid or a base to form the 6-(perfluoroalkyl)uracil compound of formula V wherein Z
3
is hydrogen; and
(c) optionally alkylating the formula V compound wherein Z
3
is hydrogen.
The present invention also relates to the novel urea compounds having the structural formula IV
wherein
Z and Z
1
are each independently C
1
-C
8
alkyl or Z and Z
1
may be taken together with the atom to which they are attached to form a 4- to 7-membered ring wherein ZZ
1
is represented by —(CH
2
)
2
O(CH
2
)
2
— or —(CH
2
)
m
— where m is an integer of B, 4, 5 or 6;
n is an integer of 1, 2, 3, 4, 5 or 6; and
Z
2
is C
1
-C
6
alkyl or benzyl optionally substituted on the phenyl ring with any combination of from one to three halogen, C
1
-C
4
alkyl or C
1
-C
4
haloalkyl groups.
DETAILED DESCRIPTION OF THE INVENTION
In a preferred embodiment of the present invention, the 2-(N,N-disubstituted)amino-4-(perfluoroalkyl)-1,3-oxazin-6-one compounds of formula I are prepared by reacting a &bgr;-amino-&bgr;-(perfluoroalkyl)acrylate compound of formula II with a base and a carbamoyl chloride compound of formula III, preferably at a temperature ranging from about −20° C. to 80° C., more preferably from about 0° C. to 50° C., in the presence of a first solvent to form a urea compound of formula IV, and reacting the formula IV urea compound with a phosphorous pentahalide or oxalyl halide, preferably at a temperature ranging from about 0° C. to 100° C., more preferably from about 20° C. to 50° C., optionally in the presence of a second solvent.
The present invention also provides a process for the preparation of 2-(N,N-disubstituted)amino-4-(perfluoroalkyl)-1,3-oxazin-6-one compounds of formula I which comprises reacting a urea compound of formula IV with a phosphorous pentahalide or oxalyl chloride, preferably at a temperature ranging from about 0° C. to 100° C., more preferably from about 20° C. to 50° C., optionally in the presence of a second solvent.
Advantageously, the present invention provides improved processes for the preparation of 2-(N,N-disubstituted)amino-4-(perfluoroalkyl)-1,3-oxazin-6-one compounds which avoid the use of phosgene iminium chloride compounds.
The present invention further relates to urea compounds having the structural formula IV which are utilized in the processes of this invention
wherein
Z and Z
1
are each independently C
1
-C
8
alkyl or Z and Z
1
may be taken together with the atom to which they are attached to form a 4- to 7-membered ring wherein ZZ
1
is represented by —(CH
2
)
2
O(CH
2
)
2
— or —(CH
2
)
m
— where m is an integer of 3, 4, 5 or 6;
n is an integer of 1, 2, 3, 4, 5 or 6; and
Z
2
is C
1
-C
6
alkyl or benzyl optionally substituted on the phenyl ring with any combination of from one to three halogen, C
1
-C
4
alkyl or C
1
-C
4
haloalkyl groups.
Preferred formula IV compounds are those wherein
Z and Z
1
are each independently C
1
-C
6
alkyl;
Z
2
is C
1
-C
4
alkyl; and
n is 1.
More preferred formula IV urea compounds of this invention are those wherein
Z and Z
1
are the same and represent methyl or ethyl;
Z
2
is methyl or ethyl; and
n is 1.
Representative formula IV compounds which are particularly useful in the processes of this invention include
ethyl 3-[(N,N-dimethylcarbamoyl)amino]-4,4,4-trifluorocrotonate, (Z)-;
methyl 3-[(N,N-dimethylcarbamoyl)amino]-4,4,4-trifluorocrotonate, (Z)-;
ethyl 3-[(N,N-diethylcarbamoyl)amino]-4,4,4-trifluorocrotonate, (Z)-;
methyl 3-[(N,N-diethylcarbamoyl)amino]-4,4,4-trifluorocrotonate, (Z)-;
ethyl 3-[(N-pyrrolodinecarbonyl)amino]-4,4,4-trifluorocrotonate, (Z)-; and
methyl 3-[(N-pyrrolodinecarbonyl)amino]-4,4,4-trifluorocrotonate, (Z)-, among others.
In another preferred embodiment of the present invention, the double bond in the formula II and IV compounds is predominately in the (Z)-configuration.
The product formula I compounds may be isolated by diluting the reaction mixture with water and extracting the product with a suitable extraction solvent. In the isol
Balasubramanian Venkataraman
BASF - Aktiengesellschaft
Maurer Barbara V.
Shah Mukund J.
LandOfFree
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