Patent ID: 8519165

Claim:
A process for the preparation of a compound of formula I, or a salt thereof wherein R 1 , R 2 , R 3 and R 4 independently represent hydrogen, halo, —NO 2 , —CN, —C(O) 2 R x1 , —OR x2 , —SR x3 , —S(O)R x4 , —S(O) 2 R x5 , —N(R x6 )R x7 , —N(R x8 )C(O)R x9 , —N(R x10 )S(O) 2 R x11 or R x12 ; X represents hydrogen or C 1-6 alkyl optionally substituted by one or more halo atoms; Y represents —C(O)—Z; Z represents aryl or heteroaryl, both of which are optionally substituted by one or more substituents selected from —OR a , halo, —NO 2 , —CN, —C(O) 2 R a1 , —SR a3 , —S(O)R a4 , —S(O) 2 R a5 , —N(R a6 )R a7 , —N(R a8 )C(O)R a9 , —N(R a10 )S(O) 2 R a11 and R a12 ; R a represents an oxy-protecting group, hydrogen or C 1-6 alkyl optionally substituted by one or more substituents selected from halo, —C(O) 2 R b1 and —N(R b2 )R b3 ; R x1 , R x2 , R x3 , R x6 , R x7 , R x8 , R x9 , R x10 , R a1 , R a3 , R a6 , R a7 , R a8 , R a9 , R a10 , R b1 , R b2 and R b3 independently represent hydrogen or C 1-6 alkyl optionally substituted by one or more halo atoms; R x4 , R x5 , R x11 , R x12 , R a4 , R a5 , R a11 and R a12 independently represent C 1-6 alkyl optionally substituted by one or more halo atoms; which process comprises reaction of a compound of formula II, or a protected derivative or salt thereof, wherein R 1 , R 2 , R 3 , R 4 are as defined above, with a compound of formula III, or a salt thereof without acylation wherein Y and X are as defined above.