1,3-Propanediol → Oxalate

Participants

Reaction Conditions

Reaction Steps

A screw-capped tube is charged with 2-[(3-iodophenyl)(1-methylpiperidin-4-yloxy)methyl]benzothiazole (example 41, 150 mg), copper(I) iodide (6.5 mg), 3,4,7,8-tetramethyl-1,10-phenanthroline (16.3 mg), cesium carbonate (223 mg), propan-1,3-diol (74 mg), ground 4 Åmolecular sieves (80 mg) and toluene (4 mL). The tube is evacuated, filled with argon and sealed. After stirring at 90° C. for 24 h, the mixture is diluted with dichloromethane, water and ammonia. After filtration and decantation, the aqueous phase is extracted with dichloromethane. The pooled organic extracts are dried over magnesium sulfate and concentrated under reduced pressure. The residue is purified by chromatography (gradient dichloromethane/methanol/ammonia from 98/2/0.5 to 95/5/0.5). The base is converted into its oxalate salt in acetone to give 3-{3-[benzothiazol-2-yl(1-methylpiperidin-4-yloxy)methyl]phenoxy}propan-1-ol, oxalate melting at 79° C.

Provenance & Evidence