Hydrochloric Acid → 3-[(3-Aminophenyl)(methylsulfonyl)methylene]-1-benzhydrylazetidine

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Reaction Steps

A mixture of 0.34 g of 1-benzhydryl-3-[(methylsulfonyl)(3-nitrophenyl)methylene]azetidine, 16 cm3 of 1 N hydrochloric acid in 8 cm3 of ethanol and 16 cm3 of tetrahydrofuran is heated under reflux. 0.17 g of iron powder is added and the reflux is maintained for 3 hours. The mixture is then cooled to room temperature and the insoluble matter is filtered off. The solution is taken up in 10 cm3 of 1 N sodium hydroxide and 50 cm3 of a saturated aqueous sodium chloride solution. The aqueous phase is extracted with 3 times 40 cm3 of dichloromethane, the extracts are combined, dried over sodium sulfate and concentrated to dryness under reduced pressure (2.7 kPa). The residue is purified 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 cyclohexane and ethyl acetate (50/50 by volume) as eluent, collecting 20 cm3 fractions. Fractions 13 to 31 are combined and concentrated to dryness under reduced pressure (2.7 kPa). The solid obtained is crystallized from 15 cm3 of ethyl ether. 0.17 g of 3-[(3-aminophenyl)(methylsulfonyl)methylene]-1-benzhydrylazetidine is obtained melting at 197° C. [NMR spectrum in DMSO-d6, T=300K, δ in ppm (250 MHz): 2.95 (3H, s, SCH3), 3.80 (2H, s, NCH2), 4.20 (2H, s, NCH2), 4.75 (1H, s, NCH), 5.25 (2H, s, NH2), 6.55 (3H, m, 3CH arom.), 7.05 (1H, t, J=7 Hz, CH arom.), 7.20 (2H, t, J=7 Hz, 2CH arom.), 7.30 (4H, t, J=7 Hz, 4CH arom.), 7.45 (4H, d, J=7 Hz, 4CH arom.)].

Provenance & Evidence