反应详情

A solution of 3.34 g of the product of Step A in 20 ml of methylene chloride was cooled to -50° C. and 2.8 ml of triethylamine were added all at once. A solution of 4 g of phthalimidoacetic acid chloride in 20 ml of methylene chloride was added thereto over 20 minutes. The mixture was stirred for one hour at 0° to -5° C. and was then poured into a decanting flask. The decanted organic phase was washed with 50 ml of demineralized water and 5 ml of a molar aqueous solution of sodium bicarbonate, and then twice with 30 ml of demineralized water. The wash water was re-extracted with 20 ml of methylene chloride and the combined organic phases were dried, rinsed and evaporated to dryness under vacuum. The 6 g of residue were chromatographed over silica gel and eluted with methylene chloride containing 5% ether. The fraction with an Rf=0.45 was evaporated to dryness and the residue was triturated with 10 ml of ether. The separated product was rinsed three times with 2 ml of ether and dried under vacuum to obtain 1.25 g of cis N-benzyl-3-phthalimido-4-chloromethyl-2-azetidinone melting at 149° C.

1. additionwas then poured into a decanting flask
2. washThe decanted organic phase was washed with 50 ml of demineralized water and 5 ml of a molar aqueous solution of sodium bicarbonate
3. extractionThe wash water was re-extracted with 20 ml of methylene chloride
4. customthe combined organic phases were dried
5. washrinsed
6. customevaporated to dryness under vacuum
7. customThe 6 g of residue were chromatographed over silica gel
8. washeluted with methylene chloride containing 5% ether
9. customThe fraction with an Rf=0.45 was evaporated to dryness
10. customthe residue was triturated with 10 ml of ether
11. washThe separated product was rinsed three times with 2 ml of ether
12. customdried under vacuum