Potassium Hydroxide → HCID 178494651, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of 1-(7-methoxy-2-methoxymethyl-3H-benzimidazol-4-yl)-2-(4-pyridyl)ethanone (0.92 g, Example 4), hydrazine hydrate (0.8 ml, 98%) and potassium hydroxide (1.6 g) in diethylene glycol (10 ml) was heated at 100° C. for 5 minutes. The resulting clear solution was the heated at 160° C. for 1 hour, then heated at 180° C. for 2 hours whilst removing water at intervals from an attached air condenser. The red solution was cooled to room temperature then poured into water (200 ml). The mixture was extracted three times with dichloromethane (100 ml). The combined extracts were dried over magnesium sulphate and then evaporated. The residue was subjected to flash chromatography on silica eluting with a mixture of methanol and dichloromethane (5:95, v/v). Fractions containing the required product were combined and evaporated. The resulting solid was combined with material similarly prepared from 0.47 g of 1-(7-methoxy-2-methoxymethyl-3H-benzimidazol-4-yl)-2-(4-pyridyl)ethanone and dissolved in dichloromethane (50 ml). The solution was washed with water (100 ml) then dried over magnesium sulphate and then evaporated. The residual white solid (1.03 g) was recrystallised from toluene to give the title compound (0.95 g) as a white solid, m.p. 154-156° C. [Elemental analysis:— C, 68.09; H, 6.43; N, 13.87%. Calculated:— C, 68.67; H, 6.44; N, 14.13%].

Provenance & Evidence