CPC C07F 5/025 (2013.01) [C07B 2200/07 (2013.01)] | 18 Claims |
1. A process for preparing a compound of Formula IV,
the process comprising:
a) reacting a compound of Formula A,
wherein PG1 is tert-butyloxycarbonyl (Boc), pthaloyl, 9-fluorenylmethyloxycarbonyl (Fmoc), triphenylmethyl (Trityl), carboxybenzyl (Cbz), trifluoroacetyl (CF3CO), benzyl (Bn), benzylidene, methanesulfonyl (Mesyl), tosyl (Ts), or acyl;
with a compound of Formula B or its salt,
in the presence of a coupling agent and a base in a nitrile solvent to obtain a reaction mixture comprising a compound of Formula I,
b) adding water to the reaction mixture to precipitate the compound of Formula I as a solid, isolating the compound of Formula I as a solid which is substantially free of dimer impurities, and converting the compound of Formula Ito the compound of Formula IV.
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