Carbon Dioxide → HCID 23688408, compound

Participants

Reaction Conditions

Reaction Steps

5-Methyl-4,6-dihydro-5H-pyrrolo[3,4-d]thiazole (155 mg) was dissolved in tetrahydrofuran (7 ml) in an argon atmosphere, and the solution was cooled to −78° C., to which tert-butyllithium (1.54N pentane solution, 0.792 ml) was added dropwise. The reaction mixture was stirred for 1 hour under ice cooling and cooled again to −78° C. After blowing carbon dioxide into the reaction mixture for 20 minutes, it was heated to room temperature. The reaction mixture was concentrated under reduced pressure to obtain crude lithium 5-methyl-4,6-dihydro-5H-pyrrolo[3,4-d]thiazole-2-carboxylate. This product was dissolved in N,N-dimethylformamide (20 ml), and to this solution, were added (±)-cis-N-[(5-chloroindol-2-yl)carbonyl]-1,2-cyclohexanediamine hydrochloride (364 mg), 1-hydroxybenzotriazole monohydrate (150 mg) and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (426 mg). After the resultant mixture was stirred overnight, the solution was concentrated, and dichloromethane and a saturated aqueous solution of sodium hydrogencarbonate were added to the residue to conduct liquid separation. The resultant organic layer was dried over anhydrous sodium sulfate, and the solvent was then distilled off under reduced pressure. The resultant residue was purified by column chromatography on silica gel (methanol:dichloromethane=7:93). A 1N ethanol solution of hydrochloric acid and ethyl acetate were added to the thus-obtained product, and powder deposited was collected by filtration to obtain the title compound (343 mg) as colorless powder.

Provenance & Evidence