Tetrabutylammonium Hydroxide → 4-(2-Hydroxy-2-(4-(5-(5-phenyl-4-propylisoxazol-3-yl)-1,2,4-oxadiazol-3-yl)phenyl)ethyl)piperazine-2-carboxylic acid

Participants

Reaction Steps

To a solution of 2-carboxypiperazine (47 mg, 0.36 mmol) in 0.5 mL dry DMSO was added tetrabutylammonium hydroxide (0.360 mL, 360 μmol, 1M in THF) and the reaction mixture was stirred at rt for 15 min. 2-bromo-1-(4-(5-(5-phenyl-4-propylisoxazol-3-yl)-1,2,4-oxadiazol-3-yl)phenyl)ethanol, Preparation 1C (30 mg, 0.066 mmol) was dissolved in 0.5 mL DMSO and added and the reaction was agitated at 400 rpm on an INNOVA® platform shaker at 80° C. for 1.5 hours. The reaction was diluted with 250 μL of MeOH and purified by HPLC (MeOH—H2O-TFA) to give 4-(2-hydroxy-2-(4-(5-(5-phenyl-4-propylisoxazol-3-yl)-1,2,4-oxadiazol-3-yl)phenyl)ethyl)piperazine-2-carboxylic acid. MS (m+1)=504. HPLC RT=2.06 min Waters Masslynx instrument equipped with a 19×100 mm 5 uM C18 column and a method of 0-100% B solvent over 15 min at a flow rate of 20 mL/min. Solvent A is 5:95 acetonitrile/water; solvent B is 95:5 acetonitrile/water and both contain 0.5% TFA.

Provenance & Evidence