How is N-{[(2-Methyl-2-propanyl)oxy]carbonyl}-L-norvaline - N-cyclohexylcyclohexanamine (CAS: 67861-96-5) typically synthesized?

N-{[(2-Methyl-2-propanyl)oxy]carbonyl}-L-norvaline - N-cyclohexylcyclohexanamine (CAS: 67861-96-5) is synthesized through a multi-step process involving coupling reactions and amide formation. The key steps include the use of a coupling agent like 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS) to activate the carboxylic acid group. The reaction is typically carried out in the presence of a base like triethylamine. The yield is usually around 70-80%.