acetic anhydride acetone anthranilic acid benzaldehyde benzyl chloride benzyl cyanide controlled substances act diethyl ether drug enforcement administration ephedrine ergonovine ergotamine ester ethylamine hydrochloric acid hypophosphorous acid iodine isosafrole methyl isobutyl ketone methylamine nitroethane phenylacetic acid phenylpropanolamine phosphorus piperidine piperonal potassium permanganate pseudoephedrine safrole salt sodium hypophosphite sulfuric acid toluene united states