1,6-Dimethoxynaphthalene → 5-Methoxy-2-tetralone

Temperature

0 °C

5-Methoxy-2-tetralone was prepared according to the method of Ames et al., J. Chem. Soc.. 1965, 2636, as follows: To a boiling solution of 100 g (0.53 mol) of 1,6-dimethoxynapthalene in 1.4 L EtOH was added 90 g (3.91 mol) sodium shavings and the mixture was stirred until all the sodium was dissolved. The reaction was cooled to 0° C., and 457 mL concentrate HCl and 395 mL H2O was added dropwise and refluxed one hour. The mixture was filtered and the filtrate was concentrated, dissolved in H2O and extracted with diethyl ether. The organic layer was concentrated and dissolved in 60 mL saturated sodium bisulfite, stirred for 20 min., then filtered. The resulting solid was freed and distilled to give the product (65% yield) as a clear oil: NMR (CDCl3)δ7.2(1H,m), 6.8(2H,m), 3.9(3H,s), 3.6(2H,s), 3.1(2H,m), 2.55(2H,m).

1. dissolutionwas dissolved
2. concentration457 mL concentrate HCl and 395 mL H2O
3. additionwas added dropwise
4. temperaturerefluxed one hour
5. filtrationThe mixture was filtered
6. concentrationthe filtrate was concentrated
7. dissolutiondissolved in H2O
8. extractionextracted with diethyl ether
9. concentrationThe organic layer was concentrated
10. dissolutiondissolved in 60 mL saturated sodium bisulfite
11. filtrationfiltered
12. distillationdistilled

ORD record

ord-eaef69bd3a47428abe230cbb7b6d4588

Source dataset

uspto-grants-1990_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04931270