Process for preparing 6-aryl-4H-S-triazolo[3,4-c]-thieno[2,3-e]-1,4-diazepines

1. A process for preparing a 6-aryl-4H-s-triazolo[3,4-c]-thieno [2,3-e]-1,4-diazepine of the formula I,

wherein

R 1 denotes a hydrogen or halogen atom or a C 1 -C 6 alkyl group,

R 2 denotes a hydrogen or halogen atom or a C 1 -C 6 alkyl, C 1 -C 6 hydroxyalkyl, C 3 -C 6 cycloalkyl group or a 5- or 6-membered oxygen-, sulphur- or nitrogen containing heterocyclic group which may optionally be substituted at the nitrogen atom by a C 1 -C 3 alkyl group, and

R 3 denotes a hydrogen or halogen atom,

in which process,

(a) a 5-aryl-1,3-dihydrothieno[2,3-e]-1,4-diazepine-2-one of the formula II

wherein R 1 and R 3 are as herein defined, is treated with a chlorinating agent, to produce a corresponding 5-aryl-2-chlorothieno[2,3-e]-1,4-diazepine of the formula III

wherein R 1 and R 3 are as herein defined,

(b) the 5-aryl-2-chlorothieno[2,3-e]-1,4-diazepine of the formula III thus obtained is reacted with an acylhydrazine of the formula IV

R2—CO—NH—NH2  (IV)

wherein R 2 is as hereinbefore defined, and

(c) the compound obtained in step (b) is treated with a base.

2. The process according to claim 1 for preparing a compound of the formula I, wherein R 1 denotes a bromine atom, R 2 denotes a methyl group and R 3 denotes a chlorine atom.

3. The process according to claim 1 , wherein steps (a) to (c) are carried out in a one-pot process.

4. The process according to claim 1 , wherein in step (a) the compound of the formula (II) is reacted with phosphorus pentachloride in the presence of an inert diluent and a tertiary amine.

5. The process according to claim 1 , wherein in step (b) the compound of the formula (III) is reacted with acetic acid hydrazide at a temperature below 100° C. in the presence of an inert diluent.

6. The process according to claim 1 , wherein in the step (c) the compound obtained in step (b) is treated with aqueous sodium hydroxide solution at a temperature from 0° C. to 50° C.

7. A process for preparing a compound of the formula I,

wherein

R 1 denotes bromine,

R 2 denotes a hydrogen or halogen atom or a C 1 -C 6 alkyl, C 1 -C 8 hydroxyalkyl, C 3 -C 6 cycloalkyl group or a 5- or 6-membered oxygen-, sulphur- or nitrogen-containing heterocyclic group which may optionally be substituted at the nitrogen atom by a C 1 -C 3 alkyl group, and

R 3 denotes a hydrogen or halogen atom.

in which process;

(a) a compound of the formula V

wherein R 3 is as hereinbefore defined, is cyclized, by the removal of water, to yield an intermediate of the formula II

wherein R 1 is hydrogen and R 3 is as hereinbefore defined:

(b) the intermediate of the formula II produced in step (a) is treated with a brominating agent to produce an intermediate of the formula II wherein R 1 is bromine;

(c) the brominated intermediate of the formula II produced in step (b) is treated with a chlorinating agent, to produce a corresponding 5-aryl-2-chlorothieno[2,3-e]-1,4-diazepine of the formula III

wherein R 1 is bromine and R 3 is as hereinbefore defined;

(d) the 5-aryl-2-chlorothieno[2,3-e]-1,4-diazepine of the formula III thus obtained is reacted with an acylhydrazine of the formula IV

R2-CO—NH—NH2  (IV)

wherein R 2 is as hereinbefore defined, and

(e) the product of step (d) obtained is treated with a base to yield the product of the formula I,

wherein steps (a) and (b) are carried out in a single pot.

8. The process according to claim 7 , wherein the compound of formula V is heated in step (a) with an acid in a high-boiling solvent.

9. The process according to claim 7 , wherein the compound obtained in step (a) is reacted with bromine in the presence of a tertiary amine.