Chlorotrimethylsilane → HCID 56605983, compound

Participants

Reaction Steps

p-Nitrobenzyl (5R, 6R)-3-(2-acetamidoethylthio)-6-[(1S)-1-hydroxyethyl]-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate, e1 (232 mg) was suspended in pyridine (3 ml) and treated with chlorotrimethylsilane (350 mg). After 15 min. the pyridine was evaporated in vacuo and ethyl acetate (20 ml) and water (20 ml) were added to the residue. After shaking, the layers were separated and the ethyl acetate layer was washed with brine, dried (MgSO4) and evaporated in vacuo. Toluene (10 ml) was added to the residue and evaporated in vacuo. The resultant trimethylsilyl ether was taken up in dry dichloromethane (6 ml), cooled to -30° and N-methylmorpholine (0.25 ml) was added. A solution of phosgene in toluene (0.90 ml; 12.5% w/w, d 0.91), diluted with dry CH2Cl2 (1 ml), was added dropwise. The mixture was allowed to warm to room temperature and the i.r. spectrum of the reaction mixture indicated that the imidoyl chloride had formed. Tetramethylguanidinium azide in dichloromethane (0.90 ml, 100 mg/ml) was added and after stirring at room temperature for 15 min. a further portion (0.20 ml) of the azide solution was added, and after another 15 min. more azide solution (0.15 ml) was added. After 15 min. the solution was diluted with dichloromethane (15 ml), water (15 ml) was added, the layers separated and the dichloromethane layer was washed with brine, dried (MgSO4) and evaporated in vacuo to dryness. Toluene (2×20 ml) was added to the residue and evaporated in vacuo. The product was chromatographed on silica gel (230-400 mesh ASTM) (15 g) eluting with ethyl acetate to give, after combination and evaporation of appropriate fractions, the title compound, e2, (210 mg), λmax (EtOH) 311 (ε10932) and 265 (11509) nm, νmax (CH2Cl2) 1785, 1705, 1525, 1345, 1150, 845 cm-1, [M+ found m/e 546.1677; C23H30N6O6SSi requires m/e 546.1714].

Provenance & Evidence