Abstract: The invention provides a composition of matter which: (i) consists of at least 90% by weight of an atropisomer (2A) and 0-10% by weight of an atropisomer of formula (2B); or (ii) consists of at least 90% by weight of an atropisomer (2B) and 0-10% by weight of an atropisomer of formula (2A); wherein the atropisomer of formula (2A) and the atropisomer of formula (2B) are represented by: or are pharmaceutically acceptable salts or tautomers thereof, wherein ring X is a benzene or pyridine ring; ring Y is selected from a benzene ring, a pyridine ring and a thiophene ring; R1 is trifluoromethyl; R2 is hydrogen; R3 is hydrogen; m is 0 or 1; n is 0, 1 or 2; Ar1 is a monocyclic aromatic ring selected from benzene and pyridine; each monocyclic aromatic ring being unsubstituted or substituted with 1 or 2 substituents R5 as defined herein; and R4; R5 when present, R6 and R7 independently selected from various substituents as defined herein.

Abstract: In one aspect, the invention relates to a process for preparing a compound of formula (XII), wherein PG is a protecting group, or a compound of formula (XI), comprising the steps of: (i) treating a compound of formula XIII, wherein PG is a protecting group, with N-methylpiperazine to form a compound of formula XII, wherein said compound of formula XII is in the form of a mixture of cis and trans isomers; (ii) combining the mixture formed in step (i) with an organic solvent and heating the solvent mixture so formed; (iii) isolating the trans-isomer of the compound of formula XII from the solvent mixture formed in step (ii); and (iv) optionally treating said trans-isomer of the compound of formula XII with an acid to form a compound of formula XI; and isolating said compound of formula XI. Further aspects of the invention relate to processes for preparing pyrimido-diazepinone derivatives using the above process and intermediates.