合成路线1

The title compound was prepared by solid-phase synthesis on a Sasrin resin. The silylated m-hydroxyphenylacetic acid (I) was attached to the resin using DCC and DMAP to yield the acid-bound resin (II). The silyl group of (II) was then removed by treatment of resin (II) with tetrabutylammonium fluoride in THF. The resultant phenol (III) was coupled to 3-bromo-1-propanol (IV) under Mitsunobu conditions to afford the bromide functionalized resin (V). Displacement of the bromide ion of (V) with 2,2-diphenylethylamine (VI) furnished the secondary amine (VII), which was subjected to reductive alkylation with aldehyde (VIII) in the presence of NaBH(OAc)3 to produce the resin-bound product (IX). Cleavage from the solid support employing trifluoroacetic acid in CH2Cl2 provided the target carboxylic acid.