4-Toluenesulfonyl chloride → HCID 18369347, compound

Participants

Reaction Steps

To a solution of para-toluenesulfonyl chloride (357 mg, 4 eq) in pyridine (0.5 ml), a solution of 5,6-bis(4-methoxyphenyl)-2-(2-hydroxyethyl)-2H-pyridazin-3-one (165 mg, 0.47 mmol) in pyridine (1.0 ml) was added, followed by stirring at room temperature for 2 hours. The reaction mixture was poured into ice water, followed by extraction with ethyl acetate. The organic layer was washed successively with water and a brine, and was then dried over anhydrous sodium sulfate. The solvent was distilled off, and N-methylpiperazine (0.15 ml, 3 eq) was added to the residue. The resulting mixture was stirred at 90-100° C. for 2 hours. After water was added to the reaction mixture, the mixture was extracted with ethyl acetate. The organic layer was washed successively with water and a brine, and then dried over anhydrous sodium sulfate. The solvent was distilled off, and ethanol was added to the residue. The resulting mixture was azeotropically boiled three times with ethanol to drive off water. The thus-obtained residue (256 mg) was separated and purified by chromatography on a silica gel column [silica gel: 8 g, chloroform/methanol (20/1)], whereby a yellow oil (165 mg, 81%) was obtained. The oil was left over in a refrigerator. Precipitated crystals were washed with a mixed solvent of methanol and diethyl ether, whereby the title compound (65 mg, 32%) was obtained as pale yellow prisms. Melting point: 109.7-110.8° C. 1H-NMR (CDCl3) δ: 2.29(3H,s), 2.46(4H,brs), 2.64(4H,brs), 2.87(2H,t,J=6.83 Hz), 3.80(3H,s), 3.81(3H,s), 4.40(2H,t,J=6.84 Hz), 6.79(2H,d,J=9.03 Hz), 6.81(2H,d,J=8.78 Hz), 6.87(1H,s), 7.02(2H,d,J=8.79 Hz), 7.12(2H,d,J=9.03 Hz). IR (KBr) cm−1: 1659,1608,1513,1295,1250,1177,1013.

Provenance & Evidence