p-Toluenesulfonic acid → HCID 22855833, compound

Participants

Reaction Steps

0.71 g (1.52 mmol) of N-[[N-(benzyloxycarbonyl)-L-phenylalanyl]methyl]-L-proline tert.butyl ester was hydrogenated in the presence of 0.58 g (3.05 mmol) of toluene-4-sulphonic acid over 5% palladium-on-carbon and the product was coupled with 0.35 g (1.52 mmol) of N-(4-methylvaleryl)-L-asparagine in an analogous manner to that described in Example 1. The crude product was purified by chromatography on silica gel using isopropanol in ethyl acetate (5%-8% gradient) for the elution. There was obtained 0.23 g of N-[[N-[N-(4-methylvaleryl)-L-asparaginyl]-L-phenylalanyl]methyl]-L-proline tert.butyl ester as a solid; MS: m/e 545 [M+H]+.

Provenance & Evidence