Patent ID: 8901319

Claim:
A method for forming a solid, highly pure compound of formula comprising: (a) providing a compound according to formula (C1); wherein: R 1 is Y is CH 2 , O, S, or NH; X 1 , X 2 , X 3 , X 4 , and X 5 are independently hydrogen, halo, trifluoromethyl, hydroxy, trifluoromethoxy, (C 1 -C 3 )-alkyl, (C 1 -C 3 )-alkoxy, or (C 1 -C 3 )-alkylthio; and each Q 1 and Q 2 is independently a protecting group that is not tert-butyldimethylsilyl (TBDMS); or wherein one of Q 1 and Q 2 is TBDMS and the other is a protecting group that is not TBDMS; or wherein one of Q 1 and Q 2 is hydrogen and the other is a protecting group that is not TBDMS; (b) forming a compound according to formula (B1) by removing the protecting groups of Q 1 and Q 2 of said compound according to formula (C1) that are not TBDMS; wherein each Q 3 and Q 4 is hydrogen; or wherein one of Q 3 and Q 4 is TBDMS and the other is hydrogen; (c) transforming said compound according to formula (B1) to a compound according to formula (A1) by the step of tert-butyldimethylsilylation, wherein said compound according to formula (A1) includes a mixture of α-OTBDMS and β-OTBDMS on its aliphatic chain, said mixture therefore defining an aliphatic chain α-OTBDMS/β-OTBDMS mixture ratio; and (d) purifying said compound according to formula (A1) to form a solid precipitate of a compound according to formula (1), said solid precipitate of said compound according to formula (1) having a higher aliphatic chain α-OTBDMS/β-OTBDMS mixture ratio than said α-OTBDMS/β-OTBDMS ratio of said compound according to formula (A1).