申请人:Mannkind Corp
公开号:US10196366B2
公开(公告)日:2019-02-05
The disclosed embodiments detail improved methods for the synthesis of diketopiperazines from amino acids. In particular improved methods for the cyclocondensation and purification of N-protected 3,6-(aminoalkyl)-2,5-diketopiperazines from N-protected amino acids. Disclosed embodiments describe methods for the synthesis of 3,6-bis-[N-protected aminoalkyl]-2,5-diketopiperazine comprising heating a mixture of an amino acid in the presence of a catalyst in an organic solvent. The catalyst is selected from the group comprising sulfuric acid, phosphoric acid, p-toluenesulfonic acid, 1-propylphosphonic acid cyclic anhydride, tributyl phosphate, phenyl phosphonic acid and phosphorous pentoxide among others. The solvent is selected from the group comprising: dimethylacetamide, N-methyl-2-pyrrolidone, diglyme, ethyl glyme, proglyme, ethyldiglyme, m-cresol, p-cresol, o-cresol, xylenes, ethylene glycol and phenol among others.
所公开的实施例详细介绍了从氨基酸合成二酮哌嗪的改进方法。特别是改进了从 N-保护氨基酸环缩合和纯化 N-保护的 3,6-(氨基烷基)-2,5-二酮哌嗪的方法。所公开的实施例描述了合成 3,6-双-[N-保护氨基烷基]-2,5-二酮哌嗪的方法,包括在有机溶剂中催化剂存在下加热氨基酸混合物。催化剂选自硫酸、磷酸、对甲苯磺酸、1-丙基膦酸环酐、磷酸三丁酯、苯基膦酸和五氧化二磷等。溶剂选自以下组别:二甲基乙酰胺、N-甲基-2-吡咯烷酮、二甘醇、乙基甘醇、丙甘醇、乙基二甘醇、间甲酚、对甲酚、邻甲酚、二甲苯、乙二醇和苯酚等。