Sodium Carbonate → 2(1H)-Pyridinone, 3-amino-4-((3,5-dimethylphenyl)thio)-5-ethyl-

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Reaction Conditions

Reaction Steps

As described for compound 8a in example 17, stannous chloride dihydrate (6.67 g, 29.6 mmoles) was added to a suspension of compound 7b (1.80 g, 5.9 mmoles) in ethyl acetate (100 ml). The mixture was heated at 70° C. under an argon atmosphere for 1 hour. After cooling to 0° C., the solution was neutralised with a saturated solution of sodium carbonate (90 ml). The precipitate was removed by filtration. The filtered phases were separated and the aqueous phase was extracted with dichloromethane. The collected organic phases were washed with a saturated aqueous sodium chloride solution (3×120 ml), dried over magnesium sulphate and evaporated. The residue was purified by column chromatography with a mixture of dichloromethane and ethanol (9:1) as eluant to give the product 8b (1.04 g, 64%) in the form of a pale beige solid: melting point 208-209° C.; NMR-1H (DMSO-d6) δ 11.51 (1H, s, NH-1), 6.81 (1H, s, H-4'), 6.68 (2H, s, H-2' and 6'), 6.56 (1H, s, H-6), 5.43 (2H, s, NH2 -3), 2.40 (2H, q, J=7.5 Hz, CH2CH3), 2.21 (6H, s, CH3 -3' and 5'), 1.04 (3H, t, J=7 Hz, CH2CH3). Anal. C15H18N2OS 0.25H2O (C, H, N, S).

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