Efficient N-acyldopamine synthesis

Abstract

N-Acyldopamines are endogenous analogs of capsaicin that exhibit cannabinoid-like activities and were identified from brain extracts. Among them, N-arachidonoyldopamine (AADA) and N-oleoyldopamine (ODA) were characterized as transient receptor potential vanilloid type V1 channel (TRPV1) ligands. Recently, it was shown that N-acyldopamines may possess diverse physiological roles in addition to their ligand activities. To study the multiple functions and action mechanisms of endogenous N-acyldopamines, a simple and efficient method of N-acyldopamine synthesis was investigated. The eighteen potentially endogenous N-acyl-dopamines and two deuterated ones, N-palmitoyl dopamine-d5 and N-stearoyl dopamine-d5, were efficiently synthesized without protective groups in CH2Cl2 under optimized conditions using propylphosphoric acid cyclic anhydride (PPACA) as a condensation agent.