5-Chloropyrimidin-2-ol hydrochloride → 1-(4-Chlorophenylsulfenyl)methyl-5-chloropyrimidin-2-one

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Reaction Steps

Potassium tert-butoxide (40 mmol) in DMF (25 ml) was added to a solution of 5-chloropyrimidin-2-one hydrochloride (20 mmol) in DMF (125 ml). The mixture was stirred at room temperature for 15 min before 1-bromomethylsulfenyl-4-chlorobenzene [see U.S. Pat. No. 2,827,492; Chem. Abstract 52 Pl 6296 d (1958)](25 mmol) was added. The resultant mixture was stirred at room temperature at 60° C. for 3h, the solvent removed at reduced pressure and the residue triturated with water and dried. The residual product was a mixture of the N- and O-alkylated isomers in the ratio 3:1 (1H NMR); yield 4.2 g (73%). The isomers were separated by their different solubilities in acetone, the less polar O-isomer being the more soluble isomer. The title compound, the N- isomer had m.p. 191° C. (acetone). (Found C45.90; H2.78. Calc. for C11H8Cl2N2OS: C46.00; H2.81) 1 H NMR (CDCl3): δ 5.25 (CH2), 7.35 (Ph, s), 8.20 and 8.50 (H-4, H-6, d, J 4 Hz). IR (KBr): 1660 cm-1 (CO). MS (70 eV; m/z (% rel. int)): 286 (4, M), 157 (11), 156 (11), 145 (33), 143 (100), 116 (27).

Provenance & Evidence