Triethylamine → 9-Fluoro-21-[2-(formylamino)-4-methylthio-1-oxobutylthio]-11beta,17-dihydroxy-16beta-methylpregna-1,4-diene-3,20-dione

Participants

Reaction Steps

To a stirred solution of N-formyl-L-methionine (11.13 gm) in dry ethyl acetate (200 ml) were added 1-hydroxybenzotriazol (9.71 gm) in dry ethyl acetate (100 ml) and dicyclohexylcarbodiimido (16.43 gm) in dry ethyl acetate (100 ml) each at room temperature. The reaction mixture was stirred for 1.5 hours. To the stirred reaction mixture was added dropwise a solution of 9-fluoro-11β,17-dihydroxy-16β-methylpregna -1,4-diene-3,20-dione-21-thiol (12.95 gm) and triethylamine (35 ml) in dry ethyl acetate (600 ml) at 0° C. for 1 hour. The reaction mixture was stirred at room temperature for 4.5 hours. The title compound (15.68 gm) was prepared by purifying the resulting reaction mixture in the same manner as in Synthetic Example 1.

Provenance & Evidence