The present invention describes the use of angiotensin-converting enzyme inhibitors (ACEI) for avoiding or delaying the appearance of allodyne, especially in diabetic patients. According to the invention, diabetes and allodyne were previously induced in rats by means of streptozotocin, some rats subsequently treated with fosinopril shown no allodyne at any time during the experiment, so that the invention being the first report showing the anti-allodyne effect of fosinopril.

The present invention relates to a process for the preparation of intermediates useful in the synthesis of [1[S(R)],2[alpha],4[beta]]-4-cyclohexyl-1-[[[2-methyl-1-oxypropoxy)propoxy](4-phenylbutyl phosphinyl]acetyl]L-proline, and the synthesis thereof, in particular as sodium salt (fosinopril sodium).