Processes for preparing...

Details Processes for preparing... Processes for preparing...

2000-07-19

2002-11-12

Shah, Mukund J. (Department: 1624)

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

Organic compounds

Heterocyclic carbon compounds containing a hetero ring...

C549S469000

Reexamination Certificate

active

06479675

ABSTRACT:

The present invention relates to a plurality of novel processes and novel intermediates for preparing 3-(1-hydroxyphenyl-1-alkoximinomethyl)dioxazines, which are known as intermediates for preparing compounds having fungicidal properties (WO 95-04728).
It has already been disclosed that certain 3-(1-hydroxyphenyl-l-alkoximinomethyl)dioxazines can be prepared starting from the corresponding hydroxyphenyl-acetates (cf. WO 95-04728). Thus, for example (5,6-dihydro-1,4,2-dioxazin-3-yl)-(2-hydroxy-phenyl)-methanone O-methyl-oxime (1) is obtained by reacting methyl hydroxyphenylacetate (a) with dihydropyran, converting the dihydropyranyl ether (b) obtained in this way with t-butyl nitrite into methyl 2-[2-(tetrahydropyran-2-yloxy)phenyl]-2-hydroximino-acetate (c), alkylating this compound with iodomethane to give methyl 2-[2-(tetrahydropyran-2-yloxy)-phenyl]-2-methoximino-acetate (d), reacting this with hydroxylamine to give 2-[2-(tetrahydropyran-2-yloxy)-phenyl]-2-methoximino-N-hydroxyacetamide (e), cyclizing the latter with dibromoethane to 3-{1-[2-(tetrahydropyran-2-yloxy)-phenyl]-1-methoximino-methyl}-5,6-dihydro-1,2,4-dioxazine (f), and finally removing the tetrahydropyranyl group using acid catalysis. This synthesis can be illustrated by the following scheme:
A major disadvantage of this process is the fact that it requires a large number of steps, some of which are of low yield, which significantly affects the profitability of this process.
It has now been found that 3-(1-hydroxyphenyl-1-alkoximinomethyl)dioxazines of the general formula
in which
A represents alkyl,
R
1
, R
2
, R
3
and R
4
are identical or different and each represent independently of one another hydrogen, halogen, cyano, nitro, respectively optionally halogen-substituted alkyl, alkoxy, alkylthio, alkylsulphinyl or alkylsulphonyl, and
Z
1
, Z
2
, Z
3
and Z
4
are identical or different and each represent independently of one another hydrogen, alkyl, halogenoalkyl or hydroxyalkyl, or
Z
1
and Z
2
or Z
1
and Z
3
or Z
3
and Z
4
form together with the respective carbon atoms that they are attached to a cycloaliphatic ring,
are obtained when
a) O-hydroxyethyl-O′-methyl-benzofurandione dioximes of the formula
 in which
A, R
1
, R
2
, R
3
, R
4
, Z
1
, Z
2
, Z
3
and Z
4
are each as defined above,
are rearranged, if appropriate in the presence of a diluent and, if appropriate, in the presence of an acid or a base, or
b) hydroxybenzoyldioxazines of the formula
 in which
R
1
, R
2
, R
3
, R
4
, Z
1
, Z
2
, Z
3
and Z
4
are each as defined above,
are reacted with an alkoxyamine of the formula
A—O—NH
2
  (IV)
 in which
A is as defined above
—or an acid addition complex thereof—
if appropriate in the presence of a diluent and, if appropriate, in the presence of an acid acceptor, or
c) hydroxyphenyl-hydroximinomethyl-dioxazines of the formula
 in which
R
1
, R
2
, R
3
, R
4
, Z
1
, Z
2
, Z
3
and Z
4
are each as defined above,
are reacted with an alkylating agent of the formula
A—X  (VI)
 in which
A is as defined above, and
X represents halogen, alkylsulphonyloxy, alkoxysulphonyloxy or arylsulphonyloxy,
if appropriate in the presence of a diluent and, if appropriate, in the presence of a base.
In the definitions, the saturated or unsaturated hydrocarbon chains, such as alkyl also in connection with hetero atoms, such as in alkoxy or alkylthio, are in each case straight-chain or branched.
The methods of the processes a-c) according to the invention are preferably employed for preparing compounds of the formula (I) in which
A represents methyl, ethyl, n- or i-propyl,
R
1
, R
2
, R
3
and R
4
are identical or different and each represent independently of one another hydrogen, halogen, cyano or nitro, or represent alkyl, alkoxy, alkylthio, alkylsulphinyl or alkylsulphonyl, each of which is optionally substituted by 1 to 5 halogen atoms and each of which has 1 to 6 carbon atoms,
Z
1
, Z
2
, Z
3
and Z
4
are identical or different and each represent independently of one another hydrogen, alkyl or hydroxyalkyl having 1 to 4 carbon atoms or halogenoalkyl having 1 to 4 carbon atoms and 1 to 5 identical or different halogen atoms, or
Z
1
and Z
2
or Z
1
and Z
3
or Z
3
and Z
4
form together with the respective carbon atoms that they are attached to a cycloaliphatic ring having five, six or seven carbon atoms.
Particular preference is given to preparing compounds of the formula (1) in which
A represents methyl or ethyl,
R
1
, R
2
, R
3
and R
4
are identical or different and each represent independently of one another hydrogen, fluorine, chlorine, bromine, cyano, nitro, methyl, ethyl, n- or i-propyl, n-, i-, s- or t-butyl, methoxy, ethoxy, n- or i-propoxy, methylthio, ethylthio, methylsulphinyl, ethylsulphinyl, methylsulphonyl or ethylsulphonyl, trifluoromethyl, trifluoroethyl, difluoromethoxy, trifluoromethoxy, difluorochloromethoxy, trifluoroethoxy, difluoromethylthio, difluorochloromethylthio, trifluoromethylthio, trifluoromethylsulphinyl or trifluoromethylsulphonyl, and
Z
1
, Z
2
, Z
3
and Z
4
are identical or different and each represent independently of one another hydrogen, methyl, ethyl, n- or i-propyl, n-, i-, s- or t-butyl, hydroxymethyl, trifluoromethyl or trifluoroethyl, or
Z
1
and Z
2
or Z
1
and Z
3
or Z
3
and Z
4
form together with the respective carbon atoms that they are attached to a cycloaliphatic ring having five, six or seven carbon atoms.
The O-hydroxyethyl-O′-methyl-benzofurandione dioximes required as starting materials in the practice of the process a) according to the invention are defined in a general way by the formula (II). In this formula (II), A, R
1
, R
2
, R
3
, R
4
, Z
1
, Z
2
, Z
3
and Z
4
preferably or particularly have those meanings already mentioned in connection with the description of the compounds of the formula (I) which can be prepared according to the invention as being preferred or particularly preferred for A, R
1
, R
2
, R
3
, R
4
, Z
1
, Z
2
, Z
3
and Z
4
.
The starting materials of the formula (II) have not been disclosed before, and as novel compounds they also form part of the subject matter of the present application.
The O-hydroxyethyl-O′-methyl-benzofurandione dioximes of the formula (II) are obtained when
process d) O-hydroxyethyl-benzofurandione monooximes of the formula
 in which
R
1
, R
2
, R
3
, R
4
, Z
1
, Z
2
, Z
3
and Z
4
are each as defined above
are reacted with an alkoxyamine of the formula (IV)
—or an acid addition complex thereof—
if appropriate in the presence of a diluent and, if appropriate, in the presence of an acid acceptor, or
process e) O-alkyl-benzofurandione dioximes of the formula
 in which
A, R
1
, R
2
, R
3
and R
4
are each as defined above
are reacted with an ethane derivative of the formula
 in which
Y
1
represents halogen, alkylsulphonyloxy, arylsulphonyloxy or alkanoyloxy, and
G represents hydrogen, or
Y
1
and G are linked to each other by a single bond, where
Y
1
represents oxygen and
G represents
 or
Y
1
and G together represent a single bond, and
Z
1
, Z
2
, Z
3
and Z
4
are each as defined above,
if appropriate in the presence of a diluent and, if appropriate, in the presence of a base, or
process f) O-hydroxyethyl-benzofurandione dioximes of the formula
 in which
R
1
, R
2
, R
3
, R
4
, Z
1
, Z
2
, Z
3
and Z
4
are each as defined above
are reacted with an alkylating agent of the formula (VI),
if appropriate in the presence of a diluent and, if appropriate, in the presence of a base, or
process m) O-oxyethyl-O′-methyl-benzofurandione dioximes of the formula
 in which
A, R
1
, R
2
, R
3
, R
4
, Z
1
, Z
2
, Z
3
and Z
4
are each as defined above and
E represents an acyl group or a ketal protecting group,
are reacted with water or an alcohol, if appropriate in the presence of a diluent and, if appropriate, in the presence of an acid or a base.
The O-hydroxyethyl-benzofurandione monooximes required as starting materials in the practice of the process d

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