Piperazin-2-one → 1-{(R*)-(4-chlorophenyl)[4-(piperazin-2-on-4-ylmethyl)phenyl]methyl}-3-[(3,5-difluorophenyl)(methylsulfonyl)methylene]azetidine

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

The operation is carried out as described in Example 87, but by stirring the reaction mixture for 4 days at 20° C., starting with 0.05 g of 1-{(R*)-[4-(chloromethyl)phenyl](4-chlorophenyl)methyl}-3-[(3,5-difluorophenyl)(methylsulfonyl)methylene]azetidine, form A isomer, 1.0 cm3 of dichloromethane, and 0.024 g of piperazin-2-one. The crude product is chromatographed on a silica gel column (particle size 0.06-0.200 mm, diameter 8 mm, height 8 cm), eluting with 80 cm3 of dichloromethane and then with a dichloromethane and methanol mixture (95/5 by volume), collecting 2.5 cm3 fractions immediately after using this eluent mixture. Fractions 3 to 8 are combined and then concentrated to dryness under reduced pressure (2.7 kPa). 0.022 g of 1-{(R*)-(4-chlorophenyl)[4-(piperazin-2-on-4-ylmethyl)phenyl]methyl}-3-[(3,5-difluorophenyl)(methylsulfonyl)methylene]azetidine, form A isomer, is obtained in the form of a white foam [1H NMR spectrum (400 MHz, CDCl3, δ in ppm) 2.62 (t, J=5.5 Hz, 2H), 2.80 (s, 3H), 3.11 (s, 2H), 3.34 (mt, 2H), 3.51 (s, 2H), 3.85 (mt, 2H), 4.34 (mt, 2H), 4.51 (s, 1H), 5.76 (unresolved complex, 1H), 6.84 (broad t, JHF=9 Hz, 1H), 6.98 (mt, 2H) from 7.20 to 7.40 (mt, 8H)].

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