Patent attributes
A compound of formula I wherein: R7 is selected from: ORA, where RA is selected from C1-4 saturated alkyl, optionally substituted by phenyl, which may bear a chloro substituent, pyridyl and furanyl; chloro; NH2; —CH2—O—C(═O)Me; R8 is OProto, where Proto is a silicon-based oxygen protecting group orthogonal to Rc; R9 is selected from H, methyl and methoxy; Rs is selected from CF3, (CF2)3CF3, CH3 and (formula 2) and Rc is selected from: (i) C(═O)—ORC1, where RC1 is a saturated C1-4 alkyl group; (ii) —CH2—O—C(═O)RC2, where RC2 is methyl or phenyl; (iii) CH2—O—Si—(RSi1)(RSi2)(RSi3), where RSi1, RSi2, RSi3 are independently selected from C1-6 a saturated alkyl group and a phenyl group; and (iv) C(—YRC3)(—YRC4) where each Y is independently O or S, and where RC3 and RC4 are independently a saturated C1-4 alkyl group, or together form a C2-3 alkylene.