中文摘要：

用N，N’-二环己基碳二亚胺（DCC）／1-羟基-苯并-三氮唑（HOBt）、1-乙基-（3-二甲基氨基丙基）碳酰二亚胺（EDC）／HOBt、2-乙氧基-1-乙氧碳酰基-1，2-二氢喹啉（EEDQ）、3-（二乙氧基磷酰基）-氧-1，2，3-苯并三嗪4（3H）-酮（DEPBT）4种常用缩合试剂合成了含N-Me二肽Boc-Leu—N—Me-Leu-OBzl，产率分别为73．5％～92．8％，65．2％～85．9％，38．9％，87．8％．比较发现反应物Boc-Leu-OH、H-N—Me-Leu-OBzl与缩合试剂DCC／HOBt的物质的量比在2．0：1．0：2．0时产率最高．利用此比例合成了3个立体异构体，产率较高．

英文摘要：

Dipeptide Boc-Leu-N-Me-Leu-OBzl containing N-Me was synthesized with four different coupling reagents. After activated by coupling reagents such as DCC/HOBt, EDC/HOBt, EEDQ and DEPBT, the yield were 73.5% ~92. 8%, 65.2% -85.9% , 38.9%, 87.8%, respectively. The yield was higher than any of other coupling reagents when the molar ratio of Boc-Leu-OH/H-N-Me-Leu-OBzl/ DCC/HOBt was 2. 0： 1, 0： 2. 0. Three stereoisomers were gotten by coupling reagent DCC/HOBt with high yield when the molar ratio was 2.0： 1.0： 2. 0