The present invention provides novel processes for the preparation of combretastatins or stilbene compounds of formulae (I) and (III)
1
wherein A is NH
2
or
2
and PG is a protecting group.
The disclosed and claimed processes include (1) Wittig condensation between a nitromethoxybenzaldehyde and a trimethoxybenzylphosphonium salt or between a trimethoxybenzaldehyde and a nitromethoxybenzylphosphonium salt to provide an intermediate compound of formula (I) wherein A is NO
2
, and subsequent iron powder reduction to provide a compound of formula (I) wherein A is NH
2
; (2) Wittig condensation of the same precursor aldehydes and phosphonium salts wherein NO
2
is replaced by NH
2
to provide a compound of formula (I) wherein A is NH
2
; and (3) a process for condensation of a compound of formula (I) wherein A is NH
2
with a doubly protected serinamide to provide an intermediate of formula (III), and subsequent hydrolysis to provide a compound of formula (I) wherein A is —NH—C(═O)CH(NH
2
)CH
2
OH, or the pharmaceutically acceptable salts thereof. Also claimed is a compound of formula (III).
本发明提供了制备化合物(I)和(III)的新型过程,其中A为NH2或2,
PG为保护基团。所披露和声明的过程包括:(1)通过Wittig缩合反应,在硝基
甲氧基苯甲醛和三
甲氧基苯基
膦酸盐或三
甲氧基苯甲醛和硝基
甲氧基苯基
膦酸盐之间进行反应,以提供化合物(I)的中间体,其中A为
NO2,随后使用
铁粉还原以提供化合物(I),其中A为NH2;(2)使用相同的前体醛和
膦酸盐进行Wittig缩合反应,其中 被NH2所取代,以提供化合物(I),其中A为NH2;以及(3)将化合物(I),其中A为NH2与双重保护的丝
氨酰胺缩合反应,以提供化合物(III)的中间体,随后
水解以提供化合物(I),其中A为—NH—C(═O)CH(NH2)CH2OH,或其药学上可接受的盐。还声明了一种化合物(III)。