Hydrochloric Acid → HCID 86589031, compound

Participants

Reaction Steps

N,N-Diisopropylethylamine (2.3 mL) is added to a cooled (0° C.) solution of 5-methylpyrazine-2-carboxylic acid (736 mg) in DMF (7 mL), followed by O-(7-azabenzotriazo-1-lyl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate (HATU, 2.26 g). The suspension is stirred at room temperature for 10 minutes, then a solution of (6S,9S,10S,11S,13S,16R,17R)-9,11-epoxy-6-fluoro-17-hydroxy-10,13,16-trimethyl-3-oxo-6,7,8,9,10,11,12,13,14,15,16,17-dodecahydro-3H-cyclopenta[a]phenanthrene-17-carboxylic acid (2 g) in DMF (7 ml) is added. After 2 hours, the reaction mixture is added dropwise to a solution of 1M HCl. The product is collected by filtration, washed repeatedly with water and dried to yield 5-methyl-pyrazine-2-carboxylic acid (6S,9S,10S,11S,13S,16R,17R)-9,11-epoxy-6-fluoro-17-carboxy-10,13,16-trimethyl-3-oxo-6,7,8,9,10,11,12,13,14,15,16,17-dodecahydro-3H-cyclopenta[a]phenanthren-17-yl ester. Selected H-NMR signals (CDCl3) δ 0.95 (3H, d), 1.10 (3H, s) 1.40 (3H, s), 2.65 (3H, s).

Provenance & Evidence