Diisopropylethylamine → HCID 68682015, compound

Participants

Reaction Steps

82 mg (0.25 mmol) (S,S)-7-(1-methoxycarbonyl-ethyl)-6-oxo-1,7-diaza-spiro[4.4]nonane-1-carboxylic acid tert-butyl ester are stirred at room temperature for three hours in 1 mL of a 4N HCl dioxane solution, evaporated, then taken up in toluene and evaporated again (twice). The residue is taken up in 2 mL dichloromethane and stirred at room temperature for 65 hours in the presence of 74 mg (0.2 mmol) tetrabutylammonium iodide, 0.035 mL (0.2 mmol) diisopropylethylamine and 30 mg (0.2 mmol) 4-bromo-but-2-en-1-ol. The reaction mixture is extracted with EtOAc and saturated aqueous sodium bicarbonate, the combined organic phases washed with brine, evaporated to dryness and the residue column chromatographed (silica gel, EtOAc/EtOH 9:1) to yield the desired product as a thick liquid.

Provenance & Evidence