Isobutyryl chloride → (S)-5-[3-(5-isopropyl-1,2,4-oxadiazol-3-yl)phenyl]-9-methylthio-1,2,3,3a,4,5-hexahydro-5,8,10,10b-tetraazabenzo[e]azulen-6-one

Participants

Reaction Conditions

Reaction Steps

(S)—N′-Hydroxy-3-(9-methylthio-6-oxo-2,3,3a,4-tetrahydro-1H,6H-5,8,10,10b-tetraazabenzo[e]azulen-5-yl)benzamidine (120 mg, 0.31 mmol) obtained in Step 1 was dissolved in pyridine (1.5 mL), and the mixture was stirred overnight at 90° C. after adding isopropylcarbonyl chloride (0.039 mL, 0.38 mmol) under ice-cooled conditions. The mixture was diluted with chloroform, washed with water and saturated brine, and the organic layer was dried over anhydrous magnesium sulfate. The residue obtained by concentrating the mixture under reduced pressure was then purified by silica gel column chromatography to give (S)-5-[3-(5-isopropyl-1,2,4-oxadiazol-3-yl)phenyl]-9-methylthio-1,2,3,3a,4,5-hexahydro-5,8,10,10b-tetraazabenzo[e]azulen-6-one (149 mg, quantitative).

Provenance & Evidence