Hydrochloric Acid → HCID 69278721, compound

Participants

Reaction Steps

4-Tert-butylphenyl isocyanate [260 mg, 1.48 mmol, dissolved in abs. THF (1 ml)] was added to a solution of compound U (320 mg crude product, approx. 1.39 mmol) in abs. THF (20 ml) under argon at RT within 10 min. The mixture was stirred for two hours and then mixed with 2N HCl solution (10 ml). The acidic reaction mixture was stirred for 10 min and then extracted with EtOAc (3×20 ml). The combined organic phases were washed with sat. NaHCO3 solution (10 ml), dried over Na2SO4 and concentrated to dryness under vacuum. The residue obtained was purified by flash chromatography (mobile solvent:cyclohexane/EtOAc=7:3). 6-Methyl-3-phenyl-1-oxa-2,8-diazaspiro[4.5]dec-2-ene-8-carboxylic acid-(4-tert-butylphenyl)amide was thus obtained as a diastereoisomer mixture (melting point from 65° C.) in a yield of 170 mg (30%).

Provenance & Evidence