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US 4,395,547 AGranted
Process for preparing 1-substituted-6-n-propyl-8-methylimidazo[1,5-d]-as-triazin-4(3H)-ones
AssigneeAmerican Cyanamid Company
InventorsSivaraman Raghu, James S. Farina, Steven L. Peake
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Abstract
This disclosure describes a novel process for the preparation of 1-(lower alkyl)substituted derivatives of 6-n-propyl-8-alkylimidazo[1,5-d]-as-triazin-4(3H)-ones which are useful as anti-asthmatic agents.
Claims1
The process of preparing compounds of the formula:
- ##STR3## wherein R is methyl, ethyl or n-propyl, R' is methyl, ethyl or phenyl, R" is alkyl, aromatic or heterocyclic which comprises condensing a ketone of the formula:
- ##STR4## wherein R, R' and R" are as hereinabove defined with a lower alkyl carbazate ester in an inert solvent at 80.degree.-135.degree. for several hours whereby a lower alkyl 3-[1-(2-n-propyl-4-methyl-5-imidazolyl)alkylidene]carbazate of the formula:
- ##STR5## is obtained;
- and cyclizing the so obtained imidazolylalkylidene carbazate ester in diphenyl ether at 150.degree.-250.degree. C. for 15-45 minutes.
1 more element
Dependencies are inferred from the claim text.