Sodium Bicarbonate → 8-tert-butyl 3-ethyl 2-(4-{[bis(1H-imidazol-2-ylmethyl)amino]methyl}benzyl)-2,8-diazaspiro[4.5]decane-3,8-dicarboxylate

Participants

Reaction Steps

Under an argon atmosphere, 4-{[bis(1H-imidazol-2-ylmethyl)amino]methyl}benzaldehyde (International Publication WO 2007/058322 pamphlet, Example 28; 21.0 g) and 8-tert-butyl 3-ethyl 2,8-diazaspiro[4.5]decane-3,8-dicarboxylate (JP 2004-002470, Example 21f; 21.2 g) were dissolved in acetic acid (4.5 mL) and anhydrous N,N-dimethylformamide (225 mL), followed by stirring at room temperature for 10 minutes. To this solution, sodium triacetoxyborohydride (17.3 g) was added. The reaction solution was stirred at room temperature for 3 hours. To the reaction solution, an aqueous sodium hydrogen carbonate solution was added, followed by extraction with ethyl acetate. The organic layer was washed with saturated brine and then dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The residue was dissolved in ethanol (300 mL) and the solution was heated at reflux for 2 hours. The reaction solution was concentrated under reduced pressure and the residue was purified by silica gel chromatography (CHROMATOREX NH (trade name), manufactured by Fuji Silysia Chemical Ltd.) (n-hexane:ethyl acetate=1:1→1:2→0:1→ethyl acetate:ethanol=19:1→9:1) to obtain the title compound (24.4 g) having the following physical properties.

Provenance & Evidence