Patent ID: 8389714

Claim:
In a process for the preparation of a compound of formula (I): wherein Ar represents an optionally substituted five- or six membered fully unsaturated ring containing at least one nitrogen atom and joined to the main ring system by means of a carbon-carbon bond; and R′ represents hydrogen or a lower acyl group having 2 to 4 carbon atoms; or a pharmaceutically-acceptable salt thereof; which process comprises a step by which a ketone of formula (II) is triflated to form a triflate of formula (III): wherein R′ is as defined above, or a protected derivative thereof; and wherein the compound (III) is further reacted to form a compound of the formula (I); the improvement comprising the triflation being conducted in the presence of a base which comprises a tertiary or heterocyclic amine such that the pK a of the conjugate acid at 25° C. is within the range 5.21 to 12, wherein the base is selected from the group consisting of pyridine, 2,6-lutidine, N-methylmorpholine, 1,4-diazabicyclo[2.2.2]octane (DABCO), trimethylamine, triethylamine, N,N-diisopropylethylamine (DIPEA), quinuclidine and 1,8-diazabicyclo-[5.4.0]undec-7-ene (DBU).