反应详情

To 45 ml. of ethanol is added 8.8 g. of ethyl 5-methyl-3-oxo-tetrahydrothiophene-2-carboxylate and 5 g. of 5-(3-methyl-2-octyl)resorcinol. The mixture is cooled in ice and hydrogen chloride is bubbled in for one-half hour. The mixture is stoppered and let stand at room temperature for 3 days. The reaction mixture is concentrated and dissolved in ether. The ether solution is extracted twice with water and once with aqueous sodium bicarbonate solution. The solution is dried over magnesium sulfate and concentrated. The 1,2-dihydro-9-hydroxy-2-methyl-7-(3-methyl-2-octyl)-4-oxo-4H-thieno-[2,3-c][1]benzopyran is crystallized from acetonitrile to give 4.65 g., m.p. 146°-149°C. Anal. Calcd. for C21H28O3S (MW = 360.6) C, 69.97; H, 7.83; Found: C, 69.89; H, 8.03. 1,2-Dihydro-9-hydroxy-2-methyl-7-(3-methyl-2-octyl)-4-oxo-4H-thieno-[2,3-c][1]benzopyran is reacted in a manner similar to that set forth in Example 8 to give 1,2-dihydro-2,4,4-trimethyl-9-hydroxy-7-(3-methyl-2-octyl)-4H-thieno-[2,3-c][1]benzopyran in 81% yield as a yellow oil. Anal. Calcd. for: C23H34O2S (MW = 374.6) C, 73.76; H, 9.15; S, 8.54; Found: C, 74.09; H, 9.68; S, 8.25.

1. temperatureThe mixture is cooled in ice
2. customhydrogen chloride is bubbled in for one-half hour
3. concentrationThe reaction mixture is concentrated
4. dissolutiondissolved in ether
5. extractionThe ether solution is extracted twice with water and once with aqueous sodium bicarbonate solution
6. dry with materialThe solution is dried over magnesium sulfate
7. concentrationconcentrated
8. customThe 1,2-dihydro-9-hydroxy-2-methyl-7-(3-methyl-2-octyl)-4-oxo-4H-thieno-[2,3-c][1]benzopyran is crystallized from acetonitrile
9. customto give 4.65 g