3,9-Dimethyl[1,3]thiazolo[3,2-a]benzimidazol-9-ium iodide → HCID 46203574, compound

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Reaction Steps

350 mg of 3,9-dimethyl[1,3]thiazolo[3,2-a]benzimidazol-9-ium iodide (1.06 mmol) were solubilized in methanol (60 mL), then 230 mg of NaOMe (4 eq) were added and the solution stirred at room temperature. After 48 h the solvent was evaporated, water was added (25 mL) and the mixture extracted with CH2Cl2 (3×25 mL). The organic layer was dried with MgSO4 and evaporated under reduced pressure. The residue was then purified by flash chromatography on silica gel (eluent: CH2Cl2) to afford 1-methyl-3-[(1Z)-1-(methylsulfanyl)prop-1-en-2-yl]-1,3-dihydro-2H-benzimidazol-2-one as a white powder (200 mg, 80% yield). Under other experimental conditions: 100 mg of iodide (III-R3=R1=Me) (0.30 mmol) were solubilised in methanol (20 mL), then 65 mg of NaOMe (4 eq) were added and the solution refluxed for 2 h. Then, the solvent was evaporated, water was added (15 mL) and the mixture extracted with CH2Cl2 (3×15 mL). 1-methyl-3-[(1Z)-1-(methylsulfanyl)prop-1-en-2-yl]-1,3-dihydro-2H-benzimidazol-2-one was recovered (87%, 62 mg) as the sole (Z) isomer.

Provenance & Evidence