Abstract: Provided are acetaic abiraterone trifluoroacetate, a preparation method and an application of same. The acetaic abiraterone trifluoroacetate is obtained through a salt-forming reaction between acetaic Abiraterone and trifluoroacetic acid. The acetaic abiraterone trifluoroacetate undergoes self-purification through recrystallization, and dissociation and recrystallization are performed on the purified abiraterone acetate trifluoroacetate, so that the obtained acetaic abiraterone has a high purity, a high yield and stable quality, and is capable of meeting the requirement for mass production of acetaic abiraterone.

Abstract: The present invention provides a process for preparing pemetrexed disodium and its intermediate, 4-(4-carbomethoxyphenyl)butanal. The process for preparing the intermediate comprises the following steps: condensing methyl 4-bromobenzoate with 3-buten-1-ol; extracting with an organic solvent during the work-up; adding silica gel to decolorize; and evaporating the organic solvent to give 4-(4-carbomethoxyphenyl)butanal. The product obtained by the present process, with a yield of higher than 80%, and a purity measured by GC of higher than 95%, may be directly used in the next bromination reaction for synthesizing pemetrexed disodium without purification. The present process is suitable for industrial production, as the operation is simple and the reagents used are cheap and readily available.