Beta-Aminobutyric Acid → 3-[(1-Cyano-4-hydroxy-7-phenoxy-isoquinoline-3-carbonyl)-amino]butyric acid

Participants

Reaction Steps

A mixture of 1-cyano-4-hydroxy-7-phenoxy-isoquinoline-3-carboxylic acid methyl ester (110 mg, 0.34 mmol) and 3-amino-butyric acid (354 mg, 3.4 mmol) (Sigma-Aldrich Corp., St. Louis Mo.) in 0.5 M NaOMe/MeOH solution (5.4 mL<2.72 mmol) was refluxed overnight and then microwaved at 120° C. for 2 h. Reaction mixture was concentrated and residue was dissolved in water (60 mL). It was acidified by 1 N HCl to pH=3-4. Precipitate was collected, rinsed with water and dried. The crude product was purified by silica gel chromatography, eluting with 5-100% EtOAc (with 0.075% acetic acid)/hexane (with 0.1% acetic acid). White solid was crystallized from fractions containing the desired produce. Solid was collected and rinsed with EtOAc and dried in vacuo to provide the title compound 5.1 mg (0.013 mmol) in 3.8% yield. LC-MS ESI−: 390.01 (M−1)−.

Provenance & Evidence