Water → 5-[4-Methyl-4-(pyrrolidin-1-ylmethyl)-4,5-dihydro-1,3-oxazol-2-yl]-2-[3-(2-methylpyrrolidin-1-yl)propoxy]pyridine

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Reaction Conditions

Reaction Steps

A solution of 4-methyl-2-{6-[3-(2-methylpyrrolidin-1-yl)propoxy]pyridin-3-yl}-4,5-dihydro-1,3-oxazole-4-carbaldehyde ax57 (273 mg, ca. 80% pure, ca. 0.66 mmol) in dichloroethane (4 ml) is treated with pyrrolidine (0.27 ml, 3.28 mmol) and sodium triacetoxyborohydride (0.35 g, 1.64 mmol), and the turbid solution is stirred at 22° C. overnight. Fresh pyrrolidine (0.145 ml, 1.64 mmol) and sodium triacetoxyborohydride (0.35 g, 1.64 mmol) are added and the solution is stirred for an additional 2 hours at room temperature. Water is then added and the mixture stirred vigorously for 5 minutes. Extraction is performed with dichloromethane until the organic extract does not contain significant UV-active spots. The combined organic layers are dried over sodium sulfate and concentrated to yield a brown oil. The product is purified by chromatography over silicagel (eluent: gradient 10 to 20% triethylamine in 90 to 80% hexanes) to afford 66 mg of 5-[4-methyl-4-(pyrrolidin-1-ylmethyl)-4,5-dihydro-1,3-oxazol-2-yl]-2-[3-(2-methylpyrrolidin-1-yl)propoxy]pyridine 33.

Provenance & Evidence