4-Methylmorpholine → 1-O-[(Z)-(1-amino-2-pyridin-4-ylethylidene)amino] 4-O-tert-butyl (2R)-2-(3-cyclohexylpropyl)butanedioate

Participants

Reaction Steps

A solution of (2R)-2-(2-tert-butoxy-2-oxoethyl)-5-cyclohexylpentanoic acid (Preparation 1) (500 mg, 1.67 mmol) in dichloromethane (20 ml) was treated with 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (354 mg, 1.85 mmol), N-methylmorpholine (203 μl, 1.85 mmol) and 1-hydroxybenzotriazole hydrate (227 mg, 1.67 mmol). (1Z)-N′-hydroxy-2-(4-pyridinyl)ethanimidamide (WO 9600720) (374 mg, 1.67 mmol) followed by N-methylmorpholine (369 μl, 3.34 mmol) were added to the reaction mixture which was stirred at room temperature for 18 hours. The reaction mixture was diluted with water (10 ml) and stirred for 20 minutes. The layers were separated via a 5 micron filter cartridge. The organic solvent was removed under reduced pressure to afford the title compound as a yellow oil (840 mg). This was used without further purification in the following step.

Provenance & Evidence