Water → 2-(p-Aminophenylthio)ethyl 2,3,4,6-tetra-O-acetyl-beta-D-galactopyranoside

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Reaction Steps

2-Bromoethyl 2,3,4,6-tetra-O-acetyl-β-D-galactopyranoside (1) (2.05 g; 4.50 mmol), p-aminothiophenol (1.2 g; 9.6 mmol), methyltrioctylammonium chloride (20 mg) and sodium hydroxide (0.3 g; 7.5 mmol) were dissolved in benzene (5 ml) and water (5 ml) The reaction mixture was stirred vigorously for 9 h (TLC: SiO2, ethyl acetate:isooctane 3:1) and worked up as above Chromatography (SiO2, ethyl acetate:isooctane 2:1) gave the title compound (20) as an amorphous solid. Yield: 1.6 g (71%). [α]D21 +7.7° (c 1.0; CHCl3); 1H-NMR (CDCl3, TMS) δ 7.25, 6.63 (ABq, 4H, JAB =8.6 Hz, aromatic H), 5.39 (d, 1H, J3,4 =3.5 Hz, H4), 5.22 (dd, 1H, J1,2 =7.9 Hz, J2,3 =10.4 Hz, H2), 5.01 (dd, 1H, H3), 4.45 (d, 1H, H1), 2.92 (t, 1H, J=6.8 Hz, S--CH2), 2.15, 2.08, 2.05, 2.00 (s, 3H each, CH3CO) ppm. 13C-NMR (CDCl3, TMS) δ 170.4, 170.3, 170.2, 169.5 (CO), 146.4, 134.5, 122.0, 115.6 (aromatic C), 101.5 (Cl), 70.9, 70.6, 68.8, 68.7, 67.0 (C2-C5, O--CH2), 61.2 (C6), 35.7 (S--CH2), 20.9, 20.7, 20.6 (CH3 --CO) ppm.

Provenance & Evidence