(2S,3R,4S)-4-amino-3,4-dihydro-2-dimethoxymethyl-3-hydroxy-2-methyl-6-nitro-2H-1-benzopyran                                                                                                                                                              在
                                                                                                                                                                                 
盐酸-N-乙基-Nˊ-(3-二甲氨基丙基)碳二亚胺                                                                                                                                  作用下,
                                                                                                                                                                                        反应 5.0h,
                                                                                                                以33%的产率得到(2S,3R,4S)-N''-cyano-N-(6-nitro-3,4-dihydro-3-hydroxy-2-methyl-2-dimethoxymethyl-2H-benzopyran-4-yl)-N'-(4-chlorophenyl)guanidine