The reaction of dl-l-phenylethylamine (I) with ethyl chloroacetate (II) by means of triethylamine in DMF gives dl-N-[(ethoxycarbonyl)methyl]-1-phenylethylamine (III), which is then treated with formic acid in refluxing xylene yielding dl-N-formyl-N-[(ethoxycarbonyl)methyl]-1-phenylethylamine (IV). The reaction of (IV) with sodium ethoxide and ethyl formate (A) in THF affords dl-N-formyl-N-[(ethoxycarbonyl)-2-hydroxyvinyl]-1-phenylethylamine (V), which, without purification, is treated with potassium thiocyanate and HCl in diisopropyl ether to give dl-l-(phenylethyl)-2-mercapto-5-ethoxycarbonylimidazole (VI). This product is finally treated with nitric acid and sodium nitrate at room temperature. The optical active drugs can be obtained starting the synthesis with the optically active amine (I).

The reaction of dl-l-phenylethylamine (I) with ethyl chloroacetate (II) by means of triethylamine in DMF gives dl-N-[(ethoxycarbonyl)methyl]-1-phenylethylamine (III), which is then treated with formic acid in refluxing xylene yielding dl-N-formyl-N-[(ethoxycarbonyl)methyl]-1-phenylethylamine (IV). The reaction of (IV) with sodium ethoxide and ethyl formate (A) in THF affords dl-N-formyl-N-[(ethoxycarbonyl)-2-hydroxyvinyl]-1-phenylethylamine (V), which, without purification, is treated with potassium thiocyanate and HCl in diisopropyl ether to give dl-l-(phenylethyl)-2-mercapto-5-ethoxycarbonylimidazole (VI). This product is finally treated with nitric acid and sodium nitrate at room temperature. The optical active drugs can be obtained starting the synthesis with the optically active amine (I).