GAS-CHROMATOGRAPHIC AND MASS-SPECTRAL ANALYSIS OF AMPHETAMINE PRODUCTS SYNTHESIZED FROM 1-PHENYL-2-NITROPROPENE

The conversion of 1-phenyl-2-nitropropene to amphetamine is investigated under a variety of reaction conditions using gas chromatography-mass spectrometry (GC-MS). This versatile intermediate is prepared by treating benzaldehyde with butylamine and nitroethane. GC-MS analysis revealed that amphetamine is produced as the major product upon catalytic reduction of 1-phenyl-2-nitropropene. However, a number of partial reduction products are also present in the mixture. Reduction of the nitropropene with a 5-molar excess of lithium aluminum hydride yields 1-phenyl-2-propanoxime as the major component. A variety of other partial reduction products and products of competing reactions are also present in this product mixture, as well as amphetamine. When this reduction is carried out with a large excess of lithium aluminum hydride, amphetamine is formed as the major product. 1-Phenyl-2-nitropropene is also converted to the ketone, 1-phenyl-2-propanone, by partial reduction and hydrolysis. Amination of this ketone under Leuckart and reductive amination conditions provide amphetamine as the principle product. GC-MS analysis reveals that these samples also contain several by-products characteristic of these routes of synthesis. © 1994 Oxford University Press.