反应详情

A mixture of 18 g. of 6-methoxy-1-tetralone, 60 g. of diethyl carbonate, 2.5 g. of sodium hydride, and 200 ml. of toluene is heated to 60°C for 5 hours. The mixture is cooled, acidified by the addition of 200 ml. of 1N hydrochloric acid, and then extracted with three 75 ml. portions of benzene. The extracts are combined, washed with water to neutrality, and dried over sodium sulfate. The mixture, containing 6-methoxy-2-ethoxycarbonyl-1-tetralone, is treated with 2.5 g. of sodium hydride at room temperature with stirring. Twenty grams of ethyl α-bromoacetate are then added and the mixture is allowed to stand for 12 hours at room temperature. The mixture is added to 500 ml. of water and extracted with methylene chloride. The extracts are combined, washed with water to neutrality, dried over sodium sulfate, and evaporated. The residue, containing 6-methoxy-2-ethoxycarbonyl-2-(ethoxycarbonylmethyl)-1-tetralone, is refluxed in 200 ml. of 6N hydrochloric acid for 24 hours and then the reflux mixture is evaporated. The residue, containing 6-methoxy-2-(carboxymethyl)-1-tetralone, is reduced by treating it with 200 ml. of ethanol containing 8 g. of sodium borohydride. After 1 hour, the mixture is acidified with the addition of 100 ml. of 3N hydrochloric acid, and the resulting mixture is extracted with several portions of methylene chloride. The extracts are combined, washed with water to neutrality, dried over sodium sulfate, and evaporated. The residue, containing 6-methoxy-1-hydroxy-1,2,3,4-tetrahydro-2-naphthylacetic acid, is hydrogenolyzed by hydrogenating with one equivalent of hydrogen in acetic acid containing 300 mg. of 5% palladium-on-barium sulfate. The hydrogenation mixture is filtered and evaporated. The residue, containing 6-methoxy-1,2,3,4-tetrahydro-2-naphthylacetic acid, is dissolved in 200 ml. of diethyl ether and the mixture is then added to a 100 ml. solution of diethyl ether containing 4 g. of diazomethane. The mixture is then evaporated to dryness. The esterified residue is dehydrogenated by adding it to 1 g. of 10% palladium-on-charcoal and heating the resulting mixture of 6 hours at 200°C. The cooled mixture is diluted with 200 ml. of chloroform, filtered, and evaporated to afford methyl 6-methoxy-2-naphthylacetate.

1. additionA mixture of 18 g
2. temperatureThe mixture is cooled
3. additionacidified by the addition of 200 ml
4. extractionof 1N hydrochloric acid, and then extracted with three 75 ml
5. washwashed with water to neutrality
6. dry with materialdried over sodium sulfate
7. additionThe mixture, containing 6-methoxy-2-ethoxycarbonyl-1-tetralone
8. additionis treated with 2.5 g
9. additionTwenty grams of ethyl α-bromoacetate are then added
10. additionThe mixture is added to 500 ml
11. extractionof water and extracted with methylene chloride
12. washwashed with water to neutrality
13. dry with materialdried over sodium sulfate
14. customevaporated
15. additionThe residue, containing 6-methoxy-2-ethoxycarbonyl-2-(ethoxycarbonylmethyl)-1-tetralone
16. temperatureis refluxed in 200 ml
17. waitof 6N hydrochloric acid for 24 hours
18. customthe reflux mixture is evaporated
19. additionThe residue, containing 6-methoxy-2-(carboxymethyl)-1-tetralone
20. additionby treating it with 200 ml
21. waitAfter 1 hour
22. additionthe mixture is acidified with the addition of 100 ml
23. extractionof 3N hydrochloric acid, and the resulting mixture is extracted with several portions of methylene chloride
24. washwashed with water to neutrality
25. dry with materialdried over sodium sulfate
26. customevaporated
27. additionThe residue, containing 6-methoxy-1-hydroxy-1,2,3,4-tetrahydro-2-naphthylacetic acid
28. filtrationThe hydrogenation mixture is filtered
29. customevaporated
30. additionThe residue, containing 6-methoxy-1,2,3,4-tetrahydro-2-naphthylacetic acid
31. dissolutionis dissolved in 200 ml
32. additionof diethyl ether and the mixture is then added to a 100 ml
33. customThe mixture is then evaporated to dryness
34. additionby adding it to 1 g
35. temperatureof 10% palladium-on-charcoal and heating
36. additionthe resulting mixture of 6 hours at 200°C
37. additionThe cooled mixture is diluted with 200 ml
38. filtrationof chloroform, filtered
39. customevaporated