Reaktion #53483

Reaktionsgleichung

dimethyl sulfoxide

triethylamine

1-{(R*)-(4-chlorophenyl)[4-(methoxycarbonyl)phenyl]methyl}azetidin-3-one

oxalyl chloride

dichloromethane

→

(R*)-(4-[chlorophenyl)[4-(methoxycarbonyl)phenyl]methyl}azetidin-3-one

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe crude product is chromatographed on a silica gel column (particle size 0.06-0.200 mm, diameter 4 cm, height 40 cm)
2. 2
   Wascheneluting with dichloromethane
3. 3
   Sonstigecollecting 250 cm3 fractions
4. 4
   Einengenconcentrated to dryness under reduced pressure (2.7 kPa)

Vorschrift

1-{(R*)-(4-chlorophenyl)[4-(methoxycarbonyl)phenyl]methyl}azetidin-3-one, form B isomer, may be prepared by carrying out the operation as described in Example 40, starting with 8.7 cm3 of oxalyl chloride, 350 cm3 of dichloromethane, 14.2 cm3 of dimethyl sulfoxide, 29.0 g of 1-{(R*)-(4-chlorophenyl)[4-(methoxycarbonyl)phenyl]methyl}azetidin-3-ole, form B isomer, and 43 cm3 of triethylamine. The crude product is chromatographed on a silica gel column (particle size 0.06-0.200 mm, diameter 4 cm, height 40 cm), eluting with dichloromethane and collecting 250 cm3 fractions. Fractions 7 to 25 are combined and then concentrated to dryness under reduced pressure (2.7 kPa). 15.5 g of 1-{(R*)-(4-[chlorophenyl)[4-(methoxycarbonyl)phenyl]methyl}azetidin-3-one, form B isomer, are obtained in the form of an orange-colored oil.

Quelle