PROCESS FOR THE PREPARATION OF PYRAZOLOPYRIDAZINE DERIVATIVES.

摘要

The invention provides a process for preparing a compound of formula (I) and pharmaceutically acceptable derivatives thereof in which: R0 is halogen, C16alkyl, C16alkoxy, C16alkoxy substituted by one or more fluorine atoms, or O(CH2)nNR4R5; R1 and R2 are independently selected from H, C16alkyl, C °16 °alkyl substituted by one or more fluorine atoms, C16alkoxy, C16hydroxyalkyl, SC16alkyl, C(O)H, C(O)C16alkyl, C16alkylsulphonyl, C16alkoxy substituted by one or more fluorine atoms, O(CH2)nCO2C16alkyl, O(CH2nSC16alkyl, (CH2)nNR4R5, (CH2)nSC16alkyl or C(O)NR4R5; with the proviso that when R0 is at the 4position and is halogen, at least one of R1 and R2 is C16alkylsulphonyl, C16alkoxy substituted by one or more fluorine atoms, O(CH2)nCO2C16alkyl, O(CH2)nSC16alkyl, (CH2)nNR4R5 or (CH2)nSC16alkyl, C(O)NR4R5; R3 is C16alkyl or NH2; R4 and R5 are independently selected from H, or C16alkyl or, together with the nitrogen atom to which they are attached, form a 48 membered saturated ring; and n is 14;which comprises oxidising a corresponding compound of formula (II) or an isomer thereof.