Diisopropyl azodicarboxylate → HCID 18447000, compound

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Reaction Steps

Cyclopropylcarbonitrile (2 ml, 27 mmol) was added to a solution of trimethylsilylazide (4.3 ml, 32.5 mmol) and trimethylaluminum (16 ml of a 2M toluene solution, 32 mmol) at 0° C. The cold bath was removed, the mixture was stirred at room temperature for 15 minutes, then warmed to 80° C. for 16 hours. The solution was carefully added to a slurry of ice and 1N HCl, followed by acidification with concentrated HCl and extraction twice with ethyl acetate. The combined organic phases were washed with saturated NaCl, dried over sodium sulfate, and evaporated to yield a solid residue. Trituration with 1:1 hexane:ethyl acetate gave 5-cyclopropyl-1H-tetrazole (CAS# 27943–07–3) as a white crystalline solid (1.5 g, 51%). 5-cyclopropyl-1H-tetrazole (0.183 g, 1.66 mmol), (5R)-3-[4-(1,1-dioxo-3,6-dihydro-2H-thiopyran-4-yl)-3,5-difluorophenyl]-5-(hydroxymethyl)-1,3-oxazolidin-2-one (WO 01/81350 A1) (0.30 g, 0.84 mmol), polystyrene-triphenylphosphine (1.73 mmol/g loading: Argonaut Technologies, Inc. Foster City, Calif. USA, 1.46 g, 2.53 mmol) and diisopropylazodicarboxylate (0.33 ml, 1.68 mmol) were reacted as described for Example 58. Purification was carried out by chromatography on silica gel with 10% acetonitrile in dichloromethane. The material obtained after chromatography was precipitated from dichloromethane solution with ether to yield the title compound as a white powder (0.28 g, 74%).

Provenance & Evidence