Trifluoroacetic acid → 4-(2-N-benzyloxycarbonyl-L-valyloxyethoxy)-benzoic acid

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Reaction Steps

To a solution of 4-methoxybenzyl 4-(2-N-benzyloxycarbonyl-L-valyloxyethoxy) benzoate (10.2 g, 19.04 mmole) in dichloromethane (100 ml) was added trifluoroacetic acid (20 ml) and the mixture was stirred 3 hours at room temperature. The solution was evaporated under reduced pressure and co-evaporated two times with toluene. The product was isolated by silica gel column chromatography. Yield: 6.9 g=87%. The product may be activated and esterified direct to a drug or converted to iodomethyl 4-(2-N-benzyloxycarbonyl-L-valyloxyethoxy)-benzoic acid as described above, that is by treatment with a base, chloroiodomethane, separation and then treatment with NaI.

Provenance & Evidence