7-[[(7R)-8-cyclopentyl-7-ethyl-5-methyl-6-oxo-7H-pteridin-2-yl]amino]-2,2-dimethyl-3H-benzofuran-4-carboxylic acid   、                                                                                      
(cis-exo)-2-methyl-3,3a,4,5,6,6a-hexahydro-1H-cyclopenta[c]pyrrol-5-ylamine                                                                                                                                                              在
                                                                                                                                                                                 O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate   、                                                                                                  
N,N-二异丙基乙胺                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
二氯甲烷                                                                                  为溶剂,
                                                                                                                                                    反应 1.5h,
                                                                                                                以19.5%的产率得到(cis-exo)-N-[2-methyl-3,3a,4,5,6,6a-hexahydro-1H-cyclopenta[c]pyrrol-5-yl]-7-[[(7R)-8-cyclopentyl-7-ethyl-5-methyl-6-oxo-7H-pteridin-2-yl]amino]-2,2-dimethyl-3H-benzofuran-4-carboxamide