Coupling of 1,2-bis(alkoxyamino)cyclohexanes with 1,3-dicarbonyl compounds: first synthesis of 1,4-dialkoxy-2,3-dihydro-1,4-diazepinium salts

The reactions of two 1,2-bis(alkoxyamino)cyclohexanes with 2-substituted malonic aldehydes, acetylacetaldehyde and acetyl-acetone gave rise to imidazolidine derivatives, whereas 1,4-dialkoxy-2,3-dihydro-2,3-cyclohexano-1,4-diazepinium salts were the only products in acidic media.