Table 1.

Reaction of 3 with H-Ala-OMe.HCl using various coupling conditions.

Coupling Condition	Yield (%)	Mp (°C)
DIC/Oxyma	88	174–176
DCC/Oxyma *	82	168–172
DIC/HOBt	72	172–175
DCC/HOBt *	70	170–174
DIC	60	170–173
DCC *	60	168–173

* NMR showed impurities corresponding to the dicyclohexylurea byproduct.