Hydrochloric Acid → HCID 20698891, compound

Participants

Reaction Steps

To a solution of 358 mg (0.62 mmol) of [4-(N-Boc-4-hydroxyprolinyl)amino-2-phenylbenzoyl]methionine methyl ester, prepared as in Example 169C, in 6 ml of methanol was added 1 ml (1 mmol) of 1 N LiOH in an ice bath and the reaction mixture was stirred for 4 hours. The reaction mixture was adjusted to pH 2-3 with 1 N HCl at the same temperature and the solvent was evaporated. The resulting residue was partitioned between chloroform and water and extracted 3 times with chloroform. The combined organic solution was washed with 1 N HCl and water, dried over anhydrous magnesium sulfate, and concentrated in vacuo to give 317 mg (92%) of [4-(4-hydroxyprolinyl)amino-2-phenylbenzoyl]methionine as a white solid. To a 5 ml of 1:1 solution of TFA and dichloromethane was added 306 mg (0.54 mmol) of the acid. After 3 hours, the reaction mixture was thoroughly evaporated under high vacuum to give an oily residue. The residue was triturated with anhydrous ether and the white solid was collected by filtration to give 254 mg (72%) of [4-(4-hydroxyprolinyl)amino-2-phenylbenzoyl]methionine trifluoroacetate: HPLC 90% (purity); mp 127 (sub.), 154-157° C. (dec.);

Provenance & Evidence