Process for preparing substituted 5-fluoro-1H-pyrazolopyridines
View Patent ↗The present application relates to a novel and efficient process for preparing novel substituted 5-fluoro-1H-pyrazolopyridines of the formula (VI) which are suitable as an intermediate for production of medicaments and for production of medicaments for treatment and/or prophylaxis of cardiovascular disorders. More particularly, the 5-fluoro-1H-pyrazolopyridines of the formula (VI) are suitable for preparation of the compound of the formula (I) which serves for production of medicaments, for production of medicaments for treatment and/or prophylaxis of cardiovascular disorders.
1. A process for preparing an aldehyde of formula (III)
in which R 1 and R 2 are each independently methyl, ethyl, isopropyl, phenyl or, together with the nitrogen atom to which they are bonded, are
comprising reacting trifluoromethanesulphonic anhydride with 2,2,3,3-tetrafluoro-1-propanol, without solvent, and
reacting the resulting 2,2,3,3-tetrafluoropropyl trifluoromethanesulphonate with a compound of formula (XIIa)
in which R 1 and R 2 are each as defined above to give a compound of formula (XIIIa)
in which R 1 and R 2 are each as defined above
and reacting the compound of formula (XIIIa) with methyl methanesulphonate to give a compound of the formula (XIVa)
in which R 1 and R 2 are each as defined above
and reacting the compound of (XIVa) with sodium hydroxide to give a compound of formula (XVa)
in which R 1 and R 2 are each as defined above
and reacting the compound of formula (XVa) with a compound of the formula (XIIa) to give the compound of formula (III).