MTDA
MTDA, or MPDA, also known as 3-methoxy-4,5-trimethylenedioxyamphetamine or as 5-methoxy-TDA, is a chemical compound of the phenethylamine and amphetamine families related to the MDxx compounds like MDMA and the EDxx compounds like EDMA. It is the 5-methoxy derivative of 3,4-trimethylenedioxyamphetamine (TDA) and the analogue of MMDA (5-methoxy-MDA) and MEDA (5-methoxy-EDA) in which the 3,4-alkylenedioxy ring is a further-expanded 3,4-trimethylenedioxy ring. It was synthesized, tested, and described by Alexander Shulgin in his 1991 book PiHKAL (Phenethylamines I Have Known and Loved).