Abstract: A novel process for the synthesis of amikacin starting from kanamycin A protected at the positions 3 and 6' is described comprising the reaction of kanamycin A with a salt of a bivalent metal cation selected from zinc, nickel, iron, cobalt, manganese, copper and cadmium in the presence of water as the solvent or co-solvent followed by the in situ reaction of the resulting complex with a reactive derivative of L-amino-2-hydroxy-butyric acid, removal of the metal cation of the protecting groups and purification of the thus obtained raw product. The acylation under these conditions is extremely selective.

Abstract: A process for the preparation of the anhydride of N-formyl-L-aspartic acid by reacting L-aspartic acid with nearly stoichiometric amounts of formic acid and acetic anhydride, under controlled conditions of temperature, reaction and addition times. The product is a known intermediate in the synthesis of .alpha.-L-aspartyl-L-phenylalanine methyl ester, a known sweetening agent.

Abstract: A process for the removal of the formyl group in N-formylated peptides or their esters is described. The N-formyl compound is reacted with hydrazine or a substituted hydrazine of formula I: ##STR1## at a pH between 1 and 3.5, keeping the pH constant during the reaction. The process is particularly useful for the preparation of aspartam.

Abstract: 2-Sulphanilamido-3-methoxypyrazine is produced in high purity and good yield, by reacting 2,3-dichloropyrazine with sulphanilamide in the presence of potassium carbonate, an aprotic solvent such as dimethylformamide and a second solvent such as toluene which is inert toward the reagents and is adapted to remove the water of reaction.

Abstract: D-tetramisole, or its l-tetramisole enantiomer, is racemized in solution in dimethylsulphoxide in the presence of a catalytically effective amount of potassium hydroxide.