Morpholine → p-Nitrobenzyl alpha-(3-phenoxymethyl-7-oxo-4-thia-2,6-diazabicyclo(3,2,0)hept-2-en-6-yl)-alpha-(1-morpholinoethylidene)acetate

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of p-nitrobenzyl α-(3-phenoxymethyl-7-oxo-4-thia-2,6-diazabicyclo(3,2,0)hept-2-en-6-yl)-α-(1-hydroxyethylidene)acetate (4.69 g.) in tetrahydrofuran (60 ml.) under a nitrogen atmosphere at 0°-5° C. was added triethylamine (1.6 ml.) followed by dropwise addition of phenyl dichlorophosphate (1.72 ml.) over 5 minutes. After stirring for 3 hours at 20° C., the reaction mixture was cooled to 0° C. and morpholine (4.0 ml.) was added dropwise over 10 minutes with the reaction temperature maintained at 0°-5° C. After stirring for 3 hours at this temperature, the tetrahydrofuran was evaporated and the residue dissolved in dichloromethane. The resulting solution was washed with water and then with saturated sodium chloride solution, dried with magnesium sulphate and evaporated to give the title compound as a yellow foam in essentially quantitative yield. The product obtained was a mixture of geometric isomers (ca. 1:1.4) about the enamine double bond and was identical to that produced in example 8.

Provenance & Evidence