反应详情

Catalytic amount of p-toluene sulphonic acid (PTSA) was added to a stirred solution of compound of Example 13 (1 g, 2.19 mmol) in xylene (50 mL). Reaction mixture was refluxed in Dean-Stark apparatus for 6 h and xylene was removed by distillation. Reaction mixture was diluted with 50 mL water, neutralized using 10% sodium bicarbonate solution and extracted using ethyl acetate (3×50 mL), washed with brine (2×10 mL), dried on sodium sulphate. The crude product obtained was purified by column chromatography (silica gel, ethylacetate/pet. ether) to obtain the title compound. Yield: 0.32 g, (33%); mp: >320° C.; 1H NMR (DMSO-d6, 300 MHz): δ 2.68 (s, 3H, CH3), 3.15 (s, 4H, 2CH2), 3.74 (s, 4H, 2CH2), 3.90 (s, 3H, OCH3), 4.65 (s, 2H, CH2), 6.76 (s, 1H, Ar), 6.88 (s, 1H, Ar), 8.06 (s, 1H, Ar), 8.44 (s, 1H, Ar); MS: m/e (EI) 437 (M+).

1. customReaction mixture
2. temperaturewas refluxed in Dean-Stark apparatus for 6 h
3. customxylene was removed by distillation
4. customReaction mixture
5. extractionextracted
6. washwashed with brine (2×10 mL)
7. customdried on sodium sulphate
8. customThe crude product obtained
9. customwas purified by column chromatography (silica gel, ethylacetate/pet. ether)