Hydrazine hydrate (1:1) → (4,7-Dihydro-1-thia-4,5-diaza-cyclopenta[a]pentalen-6-yl)-(3,4-dimethoxy-phenyl)-amine

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Reaction Steps

A mixture of 5,6-Dihydro-cyclopenta[b]thiophen-4-one (1.0 g, 7.4 mmol) and 4-Isothiocyanato-1,2-dimethoxy-benzene (1.5 g, 7.2 mmol) in THF (2.0 mL) was added to lithium hexamethyl disilane (7.0 mL, 7.2 mmol) dropwise at room temperature. The reaction mixture was stirred for 8 hr. Hydrazine monohydrate (0.4 mL, 7.9 mmol) and glacial acetic acid (0.5 mL) were added to the reaction mixture, which was then heated at the reflux temperature for 24 hr. The resulting mixture was added to water (30 mL) and then extracted with ethyl acetate. The target product was purified by gravity column chromatography (50% EtOAc in hexane) to give (4,7-Dihydro-1-thia-4,5-diaza-cyclopenta[a]pentalen-6-yl)-(3,4-dimethoxy-phenyl)-amine as brown solid in 30% yield.

Provenance & Evidence