Methyl 3-oxovalerate → 2-[(4-{2-[Heptyl(3-oxopentanoyl)amino]ethyl}-1,3-thiazol-2-yl)thio]-2-methylpropionic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

2-({4-[2-(Heptylamino)ethyl]-1,3-thiazol-2-yl}thio)-2-methylpropionic acid tert-butyl ester (3.0 g) synthesized in Example 303-2 and 3-keto-n-valeric acid methyl ester (1.46 g) were dissolved in xylene (10 mL), and the mixture was stirred at 135° C. for 8 hr. After cooling to room temperature, the solution was directly packed and purified by silica gel chromatography (elution solvent; hexane:ethyl acetate=1:1) to give 2-[(4-{2-[heptyl(3-oxopentanoyl)amino]ethyl}-1,3-thiazol-2-yl)thio]-2-methylpropionic acid tert-butyl ester (1.6 g) as a colorless oil. The present compound was used in the next step without particular purification. The title compound was obtained by an operation similar to that of Example 446 for the steps after cyclization reaction using hydrazine monohydrate.

Provenance & Evidence