Potassium Phosphate, Tribasic → 3-Methoxy-2-oxo-3-[[(phenylmethoxy)carbonyl]amino]-1-azetidinesulfonic acid, tetrabutylammonium salt

Participants

Reaction Conditions

Reaction Steps

To a stirring solution of lithium methoxide (667 mg) in anhydrous methanol (10 ml) at -78° C. is added a solution of 2-oxo-3-[N-chloro-N-[(phenylmethoxy)carbonyl]amino]-1-azetidinesulfonic acid, tetrabutylammonium salt (0.94 g) in dry dimethylformamide (10 ml). After stirring the mixture at -78° C. for 1 hour, it is poured into 0.5M monobasic potassium phosphate solution and extracted with methylene chloride (three 150 ml portions). The combined extracts are dried (sodium sulfate) and solvent is removed in vacuo to given an oil (0.83 g). The desired product is obtained by chromatographing the oil on silica gel (100 g) and eluting with 4-5% methanol in methylene chloride to give an oil (513 mg): λmax (neat) 1767, 1720 cm-1 ; NMR (CDCl3) δ 3.40 (S, OCH3), 3.03 (ABq, J=6.5 Hz, H4), 5.08 (S, CH2), 6.00 (S, NH), 7.27 (S, aromatic).

Provenance & Evidence