CPC C07D 495/04 (2013.01) | 13 Claims |
1. A method of synthesizing a compound of formula 1b, the method comprising:
reacting compound 4 with compound 5a to produce compound 6a;
reducing compound 6a with hydrogen over a platinum-vanadium catalyst, with aqueous ammonia, in 2-methyl tetrahydrofuran as a solvent, to form compound 7;
coupling compound 7 with compound 2 using N,N,N′,N′-tetramethylchloroformamidinium hexafluorophosphate and 2,6-lutidine, in THF, to produce a THF adduct of compound 1; and
dissolving the THF adduct of compound 1 in an aqueous mixture of methanesulfonic acid in iso-propyl alcohol, to provide a pure form of compound 1b.
|