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Method and novel intermediate products for producing isoxazolin-3-yl-acylbenzenenes

Imported: 23 Feb '17 | Published: 22 Oct '02

Wolfgang von Deyn, Joachim Gebhardt, Michael Rack, Rene Lochtman, Norbert Götz, Michael Keil, Matthias Witschel, Helmut Hagen, Ulf Misslitz, Ernst Baumann

USPTO - Utility Patents

Abstract

The present invention describes a process for preparing isoxazoles of the formula I

where:

R

1 is hydrogen, C

1-C

6-alkyl,

R

2 is hydrogen, C

1-C

6-alkyl,

R

3, R

4, R

5 are each hydrogen, C

1-C

6-alkyl or R

4 and R

5 together from a bond,

R

6 is a heterocysclic ring,

n is 0, 1 or 2;

which comprises preparing an intermediate of the formula VI

where R

1, R

3, R

4 and R

5 are each as defined above, followed by halogenation, thiomethylation, oxidation and acylation to give compounds of the formula I.

Furthermore, the invention describes novel intermediates for preparing the compounds of the formula I and novel processes for preparing the intermediates.

Claims

1. A process for preparing a (dihydro)isoxazole of formula I

wherein

which comprises preparing an intermediate of formula VI

and subsequently introducing the radical C(O)—R

6 and converting the NH

2 group into the S(O)

nR

2 radical by a reaction sequence comprising

to give the (dihydro)isoxazole of formula I,

and which further comprises preparing a (dihydro)isoxazole of formula V

by reacting an oxime of formula III

with a compound of formula IV

in the presence of a base.

2. The process of claim 1 which further comprises preparing the intermediate of formula VI by reducing the nitro group of the (dihydro)isoxazole of formula V.

3. The process of claim 1, wherein

4. The process of claim 1, wherein R

2 is hydrogen.

5. The process of claim 4, which further comprises preparing the intermediate of formula VI by reducing the nitro group of the (dihydro)isoxazole of formula V.

6. The process of claim 4, wherein