Reaktion #96112

Reaktionsgleichung

N-bromosuccinimide

p-nitrobenzyl α-[4-methoxymethylthio-3-phenoxyacetamido-2-oxo-azetidin-1-yl]-α-(1-hydroxyethylidene)acetate

morpholine

methanesulfonyl chloride

→

p-nitrobenzyl α-[4-methoxymethylthio-3-phenoxyacetamido-2-oxo-azetidin-1-yl]-α-(1-morpholino-2-bromoethylidene)acetate

Ausbeute 52.0%

p-nitrobenzyl α-[4-methoxymethylthio-3-phenoxyacetamido-2-oxo-azetidin-1-yl]-α-(1-morpholinoethylidene)acetate

Ausbeute 14.0%

Lösungsmittel

triethylamine

water

tetrahydrofuran

tetrahydrofuran

tetrahydrofuran

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigecools to -40° C. under nitrogen atmosphere
2. 2
   workup.WAITfor 45 minutes at 0° C
3. 3
   workup.WAITkeeps at 0° C. for 2 hours
4. 4
   workup.WAITkeeps at 0° C. for 1.5 hour
5. 5
   Sonstigeremoves the separated oily material, and extracts with ethyl acetate
6. 6
   Trocknendried over magnesium sulfate
7. 7
   Sonstigeevaporated
8. 8
   SonstigePurification of the obtained residual oil (1.4 g) by chromatography over silica gel containing 5% water (20 g)

Vorschrift

One dissolves p-nitrobenzyl α-[4-methoxymethylthio-3-phenoxyacetamido-2-oxo-azetidin-1-yl]-α-(1-hydroxyethylidene)acetate (1.06 g) in tetrahydrofuran (10 ml), cools to -40° C. under nitrogen atmosphere, adds triethylamine (489 mg) dissolved in tetrahydrofuran (1 ml) and methanesulfonyl chloride (252 mg) dissolved in tetrahydrofuran (1 ml), and stirs for 30 minutes at -40° C. and for 45 minutes at 0° C. To this solution, one adds morpholine (209 mg) dissolved in tetrahydrofuran (1 ml), keeps at 0° C. for 2 hours, adds N-bromosuccinimide (392 mg), keeps at 0° C. for 1.5 hour, adds water, and removes the separated oily material, and extracts with ethyl acetate. The extract solution and the removed oily material is combined, dried over magnesium sulfate, and evaporated. Purification of the obtained residual oil (1.4 g) by chromatography over silica gel containing 5% water (20 g) gives p-nitrobenzyl α-[4-methoxymethylthio-3-phenoxyacetamido-2-oxo-azetidin-1-yl]-α-(1-morpholino-2-bromoethylidene)acetate (700 mg; Yield: 52%) and p-nitrobenzyl α-[4-methoxymethylthio-3-phenoxyacetamido-2-oxo-azetidin-1-yl]-α-(1-morpholinoethylidene)acetate (170 mg; Yield: 14%).

Quelle