Diphenyl chlorophosphate → HCID 178503450, compound

Participants

Reaction Steps

To a solution of p-nitrobenzyl (5R, 6S)-6-[1-(R)-hydroxyethyl]-3,7-dioxo-1-azabicyclo[3.2.0]heptane-2-carboxylate (1.40 g, 4.0 mmol) in 50 mL of dry acetonitrile, at 0° C. under N2, was added dropwise diisopropylethylamine (0.76 mL, 4.4 mmol) followed by diphenyl chlorophosphate (0.91 mL, 4.1 mmol). After stirring the reaction mixture at room temperature for 1 h, diisopropylethylamine (0.76 mL, 4.4 mmol) was added and then a solution of 2-methylthio-3-methyl-1-(2-mercaptoethyl)imidazolium trifluoromethanesulfonate (2.0 g, 5.9 mmol) in 5 mL of acetonitrile was added dropwise. The reaction mixture was kept at room temperature for 1.5 h and was then concentrated in vacuo to give a gum. This gum was taken up in H2O and applied to a C18 reverse-phase column. Elution with H2O, then 20% acetonitrile-H2O and finally 30% acetonitrile-H2O, followed by lyophilization of the appropriate fractions afforded the product (0.90 g, 30%) as a light yellow solid. ir(KBr) νmax : 3380 (br, OH), 1770 (β-lactam CO) cm-1 ; 'Hnmr (d6 -acetone) δ: 8.35 (br s, 1H), 8.24, 7.78 (AB q, J=8.8 Hz, 4H, aromatic), 7.89 (br s, 1H), 7.25-6.91 (m, 10H, diphenylphosphate), 5.50, 5.25 (ABq, J=12 Hz, 2H, benzylic), 4.75-4.27 (m, 3H), 4.03 (s, 3H, N-Me), 4.15-2.75 (m, 8H), 2.53 (s, 3H, S-Me), 1.22 (d, J=6.2 Hz, 3H, --CHMe).

Provenance & Evidence