Process for the preparation of pyrazine compounds
AssigneeSmithKline Beecham Corporation
InventorsDean David Edney, Andrew Kennedy
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Abstract
The present invention relates to a process for the preparation of both the phenyl pyrazine derivative 2,6-diamino-3-(2,3,5-trichlorophenyl)pyrazine and an intermediate in the synthesis of 2,6-diamino-3(2,3,5-trichlorophenyl)pyrazine, 2-{[Cyano-(2,3,5-trichlorophenyl)-methyl]-amino}-acetamidine or a salt thereof.
Claims7
A process for the preparation of 2-{[Cyano-(2,3,5-trichlorophenyl)-methyl]-amino}-acetamidine or a salt thereof which process comprises the steps of:
- (i) reaction of an acid salt of aminoacetamidine with a source-of cyanide;
- and
- (ii) reaction of the product of step (i) with 2,3,5-trichlorobenzaldehyde.
A process as claimed in any preceding claim wherein the reaction step (ii) is conducted at elevated temperatures.
A process as claimed in any preceding claim wherein the aminoacetamide is in excess.
A process as claimed in any preceding claim wherein the source of cyanide is selected from potassium cyanide, sodium cyanide, and tetrabutylammonium cyanide.
A process for the preparation of 2,6-diamino-3-(2,3,5-trichlorophenyl)pyrazine or a pharmaceutically acceptable derivative thereof which comprises carrying out the process of any preceding claims and further comprises cyclisation and oxidation of 2-{[Cyano-(2,3,5-trichlorophenyl)-methyl]-amino}-acetamidine or a salt thereof.
Dependencies are inferred from the claim text.