New synthetic route to N,N′-diaminohydantoins from hydrazido pyridinium salts
Abstract
α-Bromoarylacetohydrazides were converted by pyridine into the corresponding arylacetylhydrazinopyridinium salts. Treated with triethylamine, these pyridinium salts afford 4-aryl-1,3-diaminohydantoins. The study of the mechanism of this unexpected reaction lead us to extend its scope to 4-arylhydantoins bearing two different substituted amino groups on nitrogens 1 and 3.