Process for making 4-methyl-4,5-dihydrotetrazolo [1,5-a] quinazolin-5-one
AssigneeImperial Chemical Industries PLC
InventorsJohn H. Marsden, Norman Harrison
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Abstract
In a process for preparing the compound 4-methyl-4,5-dihydrotetrazolo [1,5-a] quinazolin-5-one having the structural formula: ##STR1## which comprises the steps of (i) bringing anthranilic acid into reaction with cyanamide at a temperature in the range of 80.degree. to 100.degree. C.; (ii) bringing the reaction product obtained by the foregoing step (i) into reaction with hydrazine hydrate in the presence of an organic solvent; then (iii) diazotizing the hydrazino compound so formed to yield a tetrazole; and finally (iv) methylating the tetrazole, the improvement which comprises using n-butanol as the organic solvent in step (ii).
Claims9
In a process for preparing the compound 4-methyl-4,5-dihydrotetrazolo[1,5-a]quinazolin-5-one having the structural formula:
- ##STR10## which comprises the steps of (i) bringing anthranilic acid into reaction with cyanamide at a temperature in the range of 80.degree. to 100.degree. C.;
- (ii) bringing the reaction product obtained by the foregoing step (i) into reaction with hydrazine hydrate in the presence of an organic solvent;
- then (iii) diazotising the hydrazino compound so formed to yield a tetrazole;
- and finally (iv) methylating the tetrazole, the improvement which comprises using n-butanol as the organic solvent in step (ii).
Dependencies are inferred from the claim text.