The present invention provides a new process for the preparation of 2S,3S-N-isobutyl-N-(2-hydroxy-3-amino-4-phenylbutyl)-p-nitrobenzenesulfony lamide hydrochloride, wherein this compound is prepared directly from the chloromethylalcohol. Importantly, the process of the present invention results in higher yields of 2S,3S-N-isobutyl-N-(2-hydroxy-3-amino-4-phenylbutyl)-p-nitrobenzenesulfony lamide hydrochloride without sacrificing its purity. The processes of the present inventin can be used to prepare not only the 2S,3S-derivative, but also the 2R,3S-, 2S,2R- and the 2R,3R-derivatives.

La presente invenzione fornisce un nuovo processo per la preparazione di 2S, cloridrato di lamide 3S-N-isobutyl-N-(2-hydroxy-3-amino-4-phenylbutyl)-p-nitrobenzenesulfony, in cui questo residuo è preparato direttamente dal chloromethylalcohol. D'importanza, il processo dell'invenzione del presente provoca i più grandi rendimenti di 2S, cloridrato di lamide 3S-N-isobutyl-N-(2-hydroxy-3-amino-4-phenylbutyl)-p-nitrobenzenesulfony senza sacrificare la relativa purezza. I processi del inventin attuale possono essere usati per preparare non soltanto il 2S, 3S-derivative, ma anche il 2r, 3s -, 2s, 2r- ed il 2R, 3R-derivatives.