Ethyl Acetate → HCID 23374174, compound

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Reaction Steps

In Example 107, reduction of the nitro group in compound 342 by reaction with stannous chloride in methanol proceeded selectively and resulted in the formation of amino derivative 343 in high yield, as follows: A mixture of thiourea 342 (0.287 g, 1 mmol) and SnCl2.2H2O (0.5 g, 2.2 mmol) in MeOH (25 mL) was refluxed for 4 hours, cooled to room temperature, then poured into EtOAc (150 mL. The mixture was sequentially washed with saturated NaHCO3 (5×20 mL) and H2O (3×20 mL), dried over MgSO4, then evaporated. The residue was chromatographed over silica gel (2×15 cm, eluant: 1% MeOH in CHCl3) to produce (4-aminophenyl)-benzyl thiourea 343 (0.192 g, 75% yield) as a white powder. Relevant data: mp 153°-155° C. (from EtOAc); 1H NMR (DMSO-d6): δ4.65 (d, 2H, J=5.7 Hz), 5.05 (br.s., 2H, NH2), 6.50 (d, 2H, J=9 Hz), 6.85 (d, 2H, J=9Hz), 7.25 (m, 5H), 7.61 (br.s., 1H, NH), 9.15 (s, 1H, NH); 13C NMR (DMSO-d6) δ47.50, 114.72, 126.96, 127.23, 127.51, 128.66, 139.57, 146.88, 181.305; MS m/e (1%): 257 (M+, 42), 256 (17), 182 (25), 165 (6), 150 (100), 108 (75), 107 (37), 106 (47), 91 (92).

Provenance & Evidence