SYNTHESIS: To a solution of 12.3 g 3-ethoxy-4-methoxyphenol (see recipe for MEM for the preparation of this phenol) in 20 mL MeOH, there was added a warm solution of 4.8 g KOH in 100 mL MeOH. There was then added 8.2 g ethyl bromide, and the mixture held at reflux on the steam bath. Within 0.5 h, severe bumping ensued. An additional 3 g ethyl bromide were added, refluxing continued for another 0.5 h, then the reaction mixture was allowed to come to room temperature and to stand overnight. It was poured into 3 volumes H2O which produced crystals spontaneously. There was added additional base, and the mixture was extracted with 3×150 mL CH2Cl2. Removal of the solvent from the pooled extracts under vacuum gave 6.4 g of 2,4-diethoxyanisole as tan crystals with a mp of 48-48.5 °C.
A mixture of 10.9 g N-methylformanilide and 12.3 g POCl3 was allowed to stand at room temperature for 0.5 h producing a deep red claret color. There was then added 6.2 g 2,4-diethoxyanisole and the mixture was heated on the steam bath for 2 h. All was poured into 200 g chipped ice, and stirred mechanically. The dark viscous gummy oil gradually became increasingly granular and finally appeared as jade-green solids. These were removed by filtration and washed with H2O, giving a wet cake weighing 18 g and having a mp (from a porous plate) of 95.5-96.5 °C. The entire crop was recrystallized from 75 mL boiling MeOH which gave, after filtering, washing lightly with cold MeOH, and air drying, 5.4 g of 2,4-diethoxy-5-methoxybenzaldehyde with a mp of 98-99 °C. A solution of 0.2 g of this aldehyde, and 0.3 g malononitrile in 2.0 mL warm EtOH was treated with a drop of triethyl-amine. There was an immediate generation of crystals which were removed by filtration, EtOH-washed, and dried to constant weight. The bright yellow needles of 2,4-diethoxy-5-methoxybenzalmalononitrile weighed 0.15 g and had a mp of 172-172.5 °C.
A solution of 5.0 g 2,4-diethoxy-5-methoxybenzaldehyde in 16 g glacial acetic acid was treated with 2.7 g nitroethane followed by 1.7 g anhydrous ammonium acetate. The mixture was heated for 2.5 h on the steam bath, then removed and diluted with a equal volume of H2O. With cooling there was the generation of a heavy crop of orange crystals which was removed, washed with 50% acetic acid, and sucked as dry as possible. The product had a mp of 97-104 °C, and there was spectrographic evidence of some unreacted starting aldehyde. A small sample was recrystallized from boiling MeOH, with considerable loss, to give an analytical sample of 1-(2,4-diethoxy-5-methoxyphenyl)-2-nitropropene as orange-yellow crystals with a mp of 112-113 °C. Anal. (C14H19NO5) C,H. The unpurified first crop was employed in the following synthesis of the corresponding amphetamine.
To a gently refluxing suspension of 2.9 g LAH in 400 mL anhydrous Et2O under a He atmosphere, there was added 4.0 g of impure 1-(2,4-diethoxy-5-methoxyphenyl)-2-nitropropene by allowing the condensing ether to drip into a shunted Soxhlet thimble apparatus containing the nitrostyrene. This effectively added a warm saturated solution of the nitrostyrene dropwise over the course of 1 h. Refluxing was maintained for 5 h and the reaction mixture was cooled with an external ice bath with the stirring continued. The excess hydride was destroyed by the cautious addition of 400 mL of 1.5 N H2SO4. When the aqueous and Et2O layers were finally clear, they were separated, and 100 g of potassium sodium tartrate was dissolved in the aqueous fraction. Aqueous NaOH was then added until the pH was above 9, and this was then extracted with 3×150 mL CH2Cl2. Removal of the solvent under vacuum produced 2.7 g of a pale amber oil that was dissolved in 300 mL anhydrous Et2O and saturated with anhydrous HCl gas. After a few minutes delay, there commenced the separation of fine white crystals of 2,4-diethoxy-5-methoxyamphetamine hydrochloride (EEM). After the crystallization was complete, these were removed by filtration, washed with Et2O and air dried, providing 2.55 g of a fine white crystalline solid with mp 158-159 °C. Anal. (C14H24ClNO3) C,H,N.
EXTENSIONS AND COMMENTARY: This particular identity and arrangement of the alkoxy groups on the amphetamine molecule, EEM, is a totally unexplored molecule. It is reasonable to assume that it would be way down in potency, but there is no way of guessing what the nature of its activity might be at the dosage that would be active.
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