Propanoic acid, 3-iodo- → HCID 53798172, compound

Participants

Reaction Steps

Synthesis of Carbohydrate Containing CAP Reagents (Tetrafluorophenyl 3-(2,3,4,6-tetra-O-acetyl-1-thio-β-D-galactopyranosyl)propionate (4a)). Tetra-O-acetyl-D-galactosyl bromide (Sigma) was converted to the thiopseudourea (TPU) derivative by treatment with thiourea in acetone according to the literature procedure (Stowell, C. P., and Lee, Y. C. (1982) Preparation of neoglycoproteins using 2-imino-2-methoxyethyl 1-thioglycosides. Methods in Enzymology, 83, 278). This TPU derivative was reacted with 3-iodopropionic acid (Aldrich) according to the literature procedure (Ponpimom, M. M., et al (1981) Cell-Specific Ligands For Selective Drug Delivery To Tissues And Organs, J. Med. Chem., 24, 1388) to give 2-carboxyethyl 2,3,4,6-tetra-O-acetyl-1-thio-β-D-galactopyranoside. The crude material was purified by flash chromatography (3.5×30 cm silica) using a gradient of methanol in methylene chloride. The product eluted with 10% methanol. Removal of solvent gave 135 mg (20% yield) of the carboxylic acid as a yellow syrup. The tetrafluorophenyl ester (4a) was prepared from 0.13 g (0.35 mmol) of the carboxylic acid by treatment with 1.5 equivalents of tetrafluorophenyl trifluoroacetate in CH2Cl2 in the presence 2 equivalents of triethylamine.

Provenance & Evidence