Ethyl chloroformate → [3-(3-Methyl-1,2,4-triazolo[4,3-b]-pyridazin-6-yl)phenyl]carbamic acid, ethyl ester

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Reaction Steps

To a solution of 10.0 g of 3-methyl-6-[3-(amino)phenyl]-1,2,4-triazolo[4,3-b]pyridazine in 1.5 liter of dichloromethane was added 4.7 ml of ethyl chloroformate and 8.9 ml of diisopropylethylamine. The mixture was stirred for 3 hours at room temperature, concentrated in vacuo to a volume of 500 ml, filtered and the solid washed with 200 ml of dichloromethane to give a tan powder, 11.4 g, mp 232°-235° C.

Provenance & Evidence