Ethanol → Naproxen Sodium

Participants

Reaction Steps

A propylene glycol solvate of a sodium salt of naproxen was prepared. To a solution of naproxen (348 mg, 1.51 mmol) in diethyl ether (10 mL) was added propylene glycol (0.200 ml, 2.72 mmol). To the clear solution was added sodium ethoxide in ethanol (21%, 0.750 mL, 2.01 mmol). The solution became slightly yellow due to the sodium ethoxide. After 1 minute, crystals began to form. After 5 minutes, the solid had completely crystallized. The solid was collected by filtration and was washed with diethyl ether (10 mL). The product was then air-dried and collected. The solvate was 2:1 naproxen Na:propylene glycol. The solid was characterized by TGA and PXRD. The TGA thermogram of naproxen sodium salt PG solvate is shown in FIG. 7, and indicates a 13.5 percent weight loss between about 75 and 150 degrees C. This weight loss is consistent with a 2:1 naproxen Na:propylene glycol solvate. The PXRD diffractogram of naproxen sodium salt PG solvate is shown in FIG. 8, and shows peaks at 2-theta angles, including but not limited to, 6.67, 9.65, 13.41, 15.77, 18.55, 20.83, 22.79, and 27.17 degrees. Any one, any two, any three, any four, any five, any six, any seven, or all eight of the above peaks or any one or any combination of peaks in FIG. 8 can be used to characterize naproxen sodium salt PG solvate.

Provenance & Evidence