Boron tribromide → 1-[Bis(4-chlorophenyl)methyl]-3-[(3-hydroxyphenyl)(methylsulfonyl)methylene]azetidine

Participants

Reaction Steps

On carrying out the operation according to the procedure of Example 32 starting with 4.8 g of 1-[bis(4-chlorophenyl)methyl]-3-[(3-methoxyphenyl)(methylsulfonyl)methylene]azetidine, 32 cm3 of a 1 M solution of boron tribromide in dichloromethane, the residue obtained is purified by chromatography on a silica gel column (particle size 0.04-0.06 mm, diameter 3 cm, height 30 cm), at a nitrogen pressure of 0.5 bar with a mixture of dichloromethane and ethanol (98/2 by volume) as eluent and collecting 20 cm3 fractions. Fractions 16 to 17 are concentrated to dryness under reduced pressure (2.7 kPa). 0.1 g 1-[bis(4-chlorophenyl)methyl]-3-[(3-hydroxyphenyl)(methylsulfonyl)methylene]azetidine is obtained, after recrystallization from 5 cm3 of diethyl ether, in the form of a solid melting at 114° C. [NMR spectrum in DMSO-d6, T=300K, δ in ppm (250 MHz): 2.92 (3H, s, SCH3), 3.80 (2H, s, NCH2), 4.20 (2H, s, NCH2), 4.80 (1H, s, NCH), 6.80 (3H, m, 3CH arom.), 7.20 (1H, t, J=7 Hz, CH arom.), 7.37 (4H, t, J=7 Hz, 4CH arom.), 7.47 (4H, d, J=7 Hz, 4 CH arom.)].

Provenance & Evidence