Aluminium lithium hydride → HCID 178519290, compound

Participants

Reaction Steps

17.7 g of methyl 1H-imidazo[4,5-c]pyridine-6-carboxylate (example D2) were added in portions to a suspension of 19.0 g lithiumaluminium hydride in 0.6 I anhydrous tetrahydrofuran under nitrogen atmosphere at 0° C. After the addition was completed, the ice/water bath was removed and the mixture was stirred at room temperature for 12 h. 30 ml ethyl acetate followed by 100 ml methanol are slowly added at 0° C. (until gas evolution has stopped). Water (50 ml) was slowly added and the resulting precipitate was filtered. The precipitate was suspended in 11 methanol and filtered through a plug of CELITE® (diatomaceous earth). The combined filtrates are evaporated under vacuum to give crude 1H-imidazo[4,5-c]pyridin-6-ylmethanol as a brown solid that was used for the next step without further purification. To a N,N-dimethylformamide solution (140 ml) of 1H-imidazo[4,5-c]pyridin-6-ylmethanol were added 28.0 g tert-butyldimethylsilyl chloride and 19.4 g imidazole. The mixture was stirred at room temperature for 12 h and then poured into ice water (2.5 I). The resulting solid was filtered, washed with 100 ml water and dissolved in 0.5 I ethyl acetate. The organic layer was dried with MgSO4 and then concentrated under vacuum to a volume of about 100 ml. 50 ml n-hexane were added and the precipitating solid was filtered and washed with 50 ml n-hexane. The filtrate was concentrated and the resulting precipitate was washed with n-hexane. Both batches of solid were combined and dried under vacuum to yield the title compound as a yellow solid.

Provenance & Evidence