p-Toluenesulfonic acid monohydrate → 3-Acetoxymethyl-7-(3-allylimidazol-2-yl)aminoceph-3-em-4-carboxylic acid

Participants

Reaction Steps

A mixture of 4-allyl-2-fluoro-1-triphenylmethyl imidazole (1.21 g.) and toluene-p-sulphonic acid monohydrate (0.635 g.) in DMF (8.5 ml.) was stirred at ambient temperature for 1 minute then at 80°. 3-Acetoxymethyl-7-aminoceph-3-em-4-carboxylic acid (0.904 g.) was added and the mixture was heated at 80° for 2.5 hours. The solution was evaporated to dryness in vacuo and water and EtOAc added to the residue. The aqueous layer was separated, evaporated to dryness, the residue redissolved in water and purified by preparative HPLC on Whatman "Partisil 10" using water/MeOH/HOAc 70:30:1 v/v/v as eluant to give 3-acetoxymethyl-7-(3-allylimidazol-2-yl)aminoceph-3-em-4-carboxylic acid (0.142 g.) having the following n.m.r. in d6DMSO+CD3COOD: 2.0 (s, 3H); 3.15 (d, 2H); 3.23 (d, 1H); 3.54 (d, 1H); 4.7 (d, 1H); 4.97 (d, 1H); 4.9- 5.2 (m, 3H); 5.48 (d, 1H); 5.8 (m, 1H); 6.3 (s, 1H).

Provenance & Evidence