Triethylamine → HCID 69114052, compound

Participants

Reaction Conditions

Reaction Steps

To a suspension of 7.3 g (31.2 mmol) ethyl 8-hydroxy-2,3-dimethyl-imidazo[1,2-a]pyridine-6-carboxylate and 7.3 g (55.2 mmol) 1,2-epoxyindane in 150 ml methanol and 15 ml water are added 8.8 ml triethylamine and the reaction mixture is heated to 50° C. for 20 h. After cooling down, 100 ml ethyl acetate are added and the precipitate is collected by filtration. A second crop of material crystallizes from the mother liquor on evaporation. The total amount of precipitate is 6.0 g, which is suspended in a mixture of 100 ml dioxane and 60 ml 2N aqueous sodium hydroxide. After boiling under reflux for 1 h, the reaction mixture is evaporated to ⅓ of its volume and diluted with 15 ml methanol. The flask is placed in an ice bath and the pH is adjusted to pH=7 by adding 6N hydrochloric acid. After 30 min, the thick suspension is diluted with 20 ml methanol and filtered by suction. A second crop of material is obtained by evaporation of the mother liquor. The total amount of crude product is 6.75 g. Further purification is achieved by filtration over silica gel using dichloromethane:methanol:acetic acid (13:1:0.2) as eluent. Crystallization from methanol/diethyl ether yields 2.3 g (22%) of the title compound as a colourless solid (m.p. 229-231° C.).

Provenance & Evidence