Pyridine-1-oxide derivative, and process for its transformation into pharmaceutically effective compounds
The invention relates to N-[2-hydroxy-3-(1-piperidinyl)-propoxy]-pyridine-1-oxide-3-carboxamidine and its optically active enantiomers. (R)-(−)-N-[2-hydroxy-3-(1-piperidinyl)-propoxy]-pyridine-1-oxide-3-carboxamidine and (S)-(+)-N-[2-hydroxy-3-(1-piperidinyl)-propoxy]-pyridine-1-oxide-3-carboxamidine. Furthermore, the invention relates to the preparation of N-[2-hydroxy-3-(1-piperidinyl)-propoxy]-pyridine-1-oxide-3-carboxyimidoyl chloride, which may be used as an active ingredient of medicaments, and the preparation of the optically active enantiomers of this compound using the compounds of the invention as intermediate substances.
1. N-[2-hydroxy-3-(1-piperidinyl)-propoxy]-pyridine-1-oxide-3-carboxamidine and its acid addition salts.
2. (R)-(−)-N-[2-hydroxy-3-(1-piperidinyl)-propoxy]-pyridine-1-oxide-3-carboxamidine and its acid addition salts.
3. (S)-(+)-N-[2-hydroxy-3-(1-piperidinyl)-propoxy]-pyridine-1-oxide-3-carboxamidine and its acid addition salts.
4. Process for the preparation of N-[2-hydroxy-3-(1-piperidinyl)-propoxy]-pyridine-1-oxide-3-carboximidoyl chloride and its acid addition salts, comprising:
a) the diazotation of 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 diazotation of N-[2-hydroxy-3-(1-piperidinyl)-propoxy]-pyridine-1-oxide-3-carboxamidine by reacting with an alkali-nitrite in the presence of hydrochloric acid, and the transformation of the obtained base into an acid addition salt.
5. 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.