Malonic Acid → HCID 86734830, compound

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of 21.44 g. (104 mmoles) of N,N'-dicyclohexylcarbodiimide in 122 ml. of methylene chloride and 15 ml. dimethylformamide at -5° C., a solution of 29.9 g. (52 mmoles) of 6-(triphenylmethylamino)-2,2-dimethyl-3-[N'-(4-methoxybenzyl)amidino]penam and 5.41 g. (52 mmoles) of malonic acid in 122 ml. methylene chloride and 15 ml. dimethylformamide is added dropwise over 2 hours. The mixture is then stirred for 24 hours at 25° C. The N,N'-dicyclohexylurea precipitate (18.6 g., 79.8% of theory) is filtered off, and the filtrate washed with six 150 ml. portions of water. It is dried over anhydrous sodium sulfate and then rotoevaporated to yield the title compound in crude form as an orange foam (32.6 g.). The crude product is divided into two equal portions for silica gel chromatography (ethyl acetate elution) affording a total of 10.61 g. (31.6%) of the purified title compound. 1H--NHR (CDCl3) ppm (δ) 1.01 (3H, s, 2--CH3); 1.44 (3H, s, 2--CH3); 3.80 (3H, s, --OCH3); 4.31-4.73 (3H, m; 3-, 5- and 6--H); 5.25 (2H, s, --CH2 --); 4H, AB, Ha within a 7.18-7.68 multiplet, Hb centered at 6.91, J= 8 Hz, CH3O--C6H4 --); 7.18-7.68 (15H, m, C6H5 --).

Provenance & Evidence