Unexpected perimidine formation in the ring opening of 1,2-dihydro-2-piperidinomethylperimidines with di-iso-butylaluminium hydride to 1-amino-8-(2-piperidinoethyl)aminonaphthalenes

This paper describes the synthesis of 1-amino-8-(2-piperidinoethyl)aminonap hthalenes. The key step in our synthesis is the ring opening of 1,2-dihydro -2-piperidinomethylperimidines with di-iso-butylaluminium hydride. Unusuall y high amounts of DIBAL-H and long reaction times were needed to effect the reaction. Unexpected perimidine formation could be demonstrated in more or less important quantities, depending on the amount of hydride used. This o bservation is remarkable since it constitutes a formal oxidation in a power ful reducing medium.