An alternate formal synthesis of Sitagliptin phosphate is disclosed from 2,4,5-trifluorobenzadehyde in 8 linear steps with an overall yield of 31%. The chiral β-amino acid moiety present in sitaglitpin is installed via an asymmetric hydrogenation followed by a stereoselective Hofmann rearrangement as the key steps. The key chiral intermediate Boc-amino acid 1 prepared by this novel route was further converted to Sitagliptin phosphate following the known literature protocol.

中文翻译：

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关键中间体（R）-3-（叔丁氧羰基氨基）-4-（2,4,5-三氟苯基）丁酸的合成和磷酸西他列汀的形式合成。

由2,4,5-三氟苯甲醛以8个线性步骤公开了磷酸西他列汀的替代形式合成，总产率为31％。西他立肽中存在的手性β-氨基酸部分是通过不对称氢化，随后进行立体选择性霍夫曼重排而安装的，这是关键步骤。按照已知的文献方法，通过该新途径制备的关键手性中间体Boc-氨基酸1被进一步转化为磷酸西他列汀。