An Investigation Into the Yields of 3,4-Methylenedioxyphenyl-2-propanone (MDP2P) From Glycidate Pre-Precursors

The use of pre-precursors to illicitly manufacture 3,4-methylenedioxyphenyl-2-propanone (MDP2P) for the synthesis of 3,4-methylenedioxymethylamphetamine (MDMA) has emerged in clandestine laboratories. Methyl 3-(3,4-methylenedioxyphenyl)-2-methyl glycidate (MMDMG) and ethyl 3-(3,4-methylenedioxyphenyl)-2-methyl glycidate (EMDMG) have recently been seized in clandestine laboratories in New South Wales, Australia. These glycidate esters can be converted to MDP2P via acid or base hydrolysis. This study investigated factors influencing MDP2P yield from MMDMG and EMDMG through both pathways. For acid hydrolysis, hydrochloric, sulphuric, phosphoric and acetic acids were examined at different reaction times and temperatures. Reactions at 100°C produced higher MDP2P yields than those at room temperature, and 18 h was sufficient for complete conversion. Hydrochloric and sulphuric acids gave the highest yields after 18 h at 100°C (79% and 78%, respectively), phosphoric acid gave moderate conversion (~30%), and acetic acid produced poor yields (< 10%). The conversion proceeded via two previously unreported diol-ester intermediates. Base hydrolysis involved heating glycidate esters with sodium hydroxide in alcohol, forming sodium piperonyl methyl ketone (PMK) glycidate, followed by reaction with aqueous acid. Heating MMDMG in methanol or EMDMG in ethanol for 5 h produced sodium PMK glycidate. This intermediate was unstable in acidic aqueous solution and rapidly converted to MDP2P at room temperature. Yields obtained using hydrochloric, sulphuric and phosphoric acids (73%, 71% and 69%, respectively) were comparable to acid hydrolysis, whereas acetic acid produced lower yields (25%). This work may assist law enforcement agencies to predict illicit drug yields from pre-precursors and support investigations into emerging illicit drug synthesis trends.