Water → HCID 70029515, compound

Participants

Reaction Steps

To a solution of 30.6 g (0.06 mol) of (E)-(6R,7R)-3-(3-iodo-propenyl)-8-oxo-7-trimethylsilanylamino-5-thia-1-aza-bicyclo[4.2.0]oct-2-ene-4-carboxylic acid trimethylsilanyl ester in 0.22 l of dichloromethane was added at 0° over 5 min a solution of 16.8 g (0.15 mol) of 1,4-diazobicyclo[2.2.2]octane in 0.15 l of acetonitrile. The dark reaction mixture was stirred at 0° for 4 h and then, 0.15 l of 2-propanol were added over 3 min, a precipitate being formed. After stirring was continued for 0.5 h, the pecipitated material was filtered off, washed with 0.1 l of 2-propanol and dried. For purification, this material was dissolved in 0.5 l of water and the pH of the solution was adjusted to 2.5 by the addition of 47% aqueous hydroiodic acid. After stirring for 15 min at 20°, a brown precipitate was filtered off and the clear solution was concentrated in vacuo to a volume of 0.25 l. Upon addition of 1.8 l of 2-propanol a precipitate formed which was isolated by filtration. The crude product was dissolved again in 0.41 of water, and, after removing insoluble material and concentration of the solution to a volume of 0.25 l, the product was precipitated by the addition of 1.5 l of 2-propanol to give 20.4 g of (E)-(6R,7R)-7-amino-3-[3-(4-aza-1-azonia-bicyclo[2,2,2]octan-1-yl)-propenyl]-8-oxo-5-thia-1-aza-bicyclo[4.2.0]oct-2-ene-2-carboxylic acid dihydroiodide as a pale-yellow solid.

Provenance & Evidence