2-[(4- 甲基苯磺酰基) 胺基] 苯甲酸甲酯(6) 与4- 氯丁腈在相转移催化剂聚乙二醇-400 和混合碱(KOH+K2CO3)作用下发生N- 烷基化反应得2-[N-(3- 氰基丙基) -4- 甲基苯磺酰胺基] 苯甲酸甲酯，经缩合关环、脱氰基、溴代、与盐酸乙脒缩合关环、脱磺酰基得2- 甲基-1,4,5,6- 四氢咪唑并[4,5-d][1] 苯并氮?(5)。另用2- 苯基苯甲酸与4- 氨基苯甲酸在N,N'- 羰基二咪唑(CDI) 作用下发生酰胺化反应得4-(2- 苯基苯甲酰胺基) 苯甲酸，与5 在CDI 作用下经酰胺化、成盐反应得盐酸考尼伐坦，总收率37.6％ ( 以6 计)。

Methyl 2-[(4-methylphenyl)sulfonamido]benzoate(6) reacted with 4-chlorobutyronitrile via N-alkylation in the presence of the phase transfer catalyst PEG-400 and mixed bases(KOH+K2CO3) to afford methyl 2-[[N-(3-cyanopropyl)-4-methylphenyl]sulfonamido]benzoate, after condensation, cyclization, decyanation,
bromination, ring-closing with acetamidine hydrochloride and then removing the sulfonyl-group, 2-methyl-1,4,5,6-tetrahydroimidazo[4,5-d][1]benzazepine(5) was obtained. Meanwhile, [1,1'-biphenyl]-2-carboxylic acid reacted with 4-aminobenzoic acid via acid-amine condensation under the action of N,N'-carbonyldiimidazole(CDI) to give 4-[(1,1'-biphenyl)-2-yl-carboxamido]benzoic acid, after reacting with 5 via acid-amine condensation reaction and
salification with hydrochloric acid, conivaptan hydrochloride was obtained with an overall yield of 37.6％(based on 6).