Dimethylformamide dimethyl acetal → HCID 20239769, compound

Participants

Reaction Steps

A mixture containing the dihydrochloride salt of 4-[(4,5-dihydro-1H-imidazol-2-yl)methyl]piperidine (8.5 g, 0.035M) and methanol (160 ml) which contained sodium methoxide (0.071M) was stirred at room temperature for 10 minutes and dimethylformamide dimethyl acetal (170 ml) was added and heated at 90° C. for 6 hrs. The excess of dimethylformamide dimethyl acetal was removed to give 4-[(4,5-dihydro-1H-imidazol-2-yl)methyl]-piperidine carboxaldehyde dimethyl acetal. To the mixture of 6-aminopenicillanic acid (6.3 g, 0.029M) and diisopropylethylamine (5.1 ml) in dried chloroform was added the solution (20 ml CHCl3 and 5 ml MeOH) of the above piperidine carboxaldehyde dimethylacetal at 0° C. The reaction was stirred at 0° C. for 1 hr and at room temperature for 3 hrs. After this period, the solvent was removed in vacuo and dissolved in 150 ml of water. The aqueous solution, washed with ethyl acetate was acidified to pH 3 with dilute hydrochloric acid and purified on Sephadex LH20 columns to give [2S-(2alpha,5alpha,6beta)]-6-[[[4-[(4,5-dihydro-1H-imidazol-2-yl)methyl]-1-piperidinyl]methylene]amino]-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid hydrochloride (8.1 g, 62% yield).

Provenance & Evidence