Dicyclohexylcarbodiimide → Pentanedioic acid tert-butyl ester 3-methoxy-14-hydroxy-6,7-didehydro-4,5alpha-epoxy-17-methylmorphinan-6-yl ester

Participants

Reaction Steps

A suspension of oxycodone free base (100 mg, 0.317 mmol) in 1.5 mL of anhydrous acetonitrile was stirred for 20 min with DIEA (0.2 mL 1.15 mmol). DMAP (63 mg, 0.516 mmol) and DCC (112 mg, 0.545 mmol) were then added to the stirred suspension. After 5 min 1-2 (150 mg, 0.8 mmol) was added, the mixture stirred for 16 h at rt, and the resulting orange suspension concentrated to an oil under reduced pressure. The concentrated mixture was stirred with 6 mL of acetone for 10 min, and the precipitated DCU removed by filtration. The filtrate was concentrated to give a brown oil. HPLC analysis of the oil indicated that the primary reaction product was 1-3. The concentrated oil was subjected to reverse phase C-18 silica gel chromatography using a gradient of 25–40% acetonitrile in 0.07% aqueous TFA as eluent. Evaporation of the eluent from the fraction containing 1-3 gave 82 mg (53% yield) of a colorless oil which was greater than >99% pure 1-3 (HPLC).

Provenance & Evidence