hours preferably for 4 to 10 hours a compound of formula iii with an excess of hydrazine in alcoholic preferably ethanolic solution reduction of the amidrazone intermediate iib into the corresponding amidine i occurs under the same conditions as those starting from amidoxime iia further objects of the present invention are compounds of general formula ii as represented in fig1 in particular those of the following formulas iv and v as l or d enantiomers and as e or z isomers or e z mixtures and as free bases or as salts thereof formed with acids the following examples further explain the improved methods of synthesis of the present invention and the synthesis of new intermediates however without restricting the invention analysis of the eluates and products obtained according to the examples was carried out with 1 h nmr hplc electrospray ms or elementary analysis the enantiomeric excess was determined according to known methods using hplc and chiral analytical columns the starting compounds of general formula iii and their manufacture are known e g wo 00 17158 75 4 g 0 126 mol of n u03b1 2 4 6 triisopropylphenylsulfonyl 3 cyano l phenylalanine 4 ethoxycarbonyl piperazide was dissolved in 1 5 l of ethanol the solution was mixed with 32 5 g 0 47 mol of hydroxylamine hydrochloride and with a solution of 25 4 g 0 24 mol of na 2 co 3 in 0 5 l of water and refluxed for 6 hours 80 u00b0 c the crude product obtained.