Pyridine-1-oxide derivative, and process for its transformation into pharmaceutically effective compounds

Process for the preparation of (R)-(+)-N-[2-hydroxy-3-(1-piperidinyl)-propoxy]-pyridine-1-oxide-3-carboximidoyl chloride and (S)-(−)-N-[2-hydroxy-3-(1-piperidinyl)-propoxy]-pyridine-1-oxide-3-carboximidoyl chloride, and their acid addition salts, comprising

• a) the diazotation of (R)-(−)-N-[2-hydroxy-3-(1-piperidinyl)-propoxy]-pyridine-1-oxide-3-carboxamidine or (S)-(+)-N-[2-hydroxy-3-(1-piperidinyl)-propoxy]-pyridine-1-oxide-3-carboxamidine by reacting with an alkali-nitrite in the presence of hydrochloric acid, or
• b) the resolution of N-[2-hydroxy-3-(1-piperidinyl)-propoxy]-pyridine-1-oxide-3-carboxamidine, and the diazotation of the obtained optically active (R)-(−) enantiomer or (S)-(+) enantiomer in the presence of hydrochloric acid by reacting with an alkali-nitrite, or
• c) the diazotation of N-[2-hydroxy-3-(1-piperidinyl)-propoxy]-pyridine-1-oxide-3-carboxamidine in the presence of hydrochloric acid by reacting with an alkali-nitrite, and the isolation of the required (R)-(+) or (S)-(−) enantiomer by resolving the obtained raceme N-[2-hydroxy-3-(1-piperidinyl)-propoxy]-pyridine-1-oxide-3-carboximidoyl chloride, or
• d) the transformation of (R)-(+)-N-[2-hydroxy-3-(1-piperidinyl)-propoxy]-pyridine-1-oxide-3-carboximidoyl chloride or (S)-(−)-N-[2-hydroxy-3-(1-piperidinyl)-propoxy]-pyridine-1-oxide-3-carboximidoyl chloride, prepared by any of the process variants under a)-c), into an acid addition salt.