Diisopropylamine → 2,2-dibutyl-3,4-dihydro-5-methoxy-1(2H)naphthalenone

Temperature

34 °C

To a solution of lithium diisopropylamide prepared from n-butyllithium (4.0 ml, 1.56 M solution in n-hexane) and diisopropylamine (0.88 ml) in freshly distillated dimethoxyethane (20 ml) was added dropwise a solution of 3,4-dihydro-5-methoxy-1(2H)-naphthalenone (881 mg) in dimethoxyethane (5 ml) at -20° C. under nitrogen gas atmospheres. The mixture was stirred at -20°~0° C. for 30 minutes and then warmed to 34° C. rapidly. To the mixture was added iodobutane (1.8 ml) in one portion. The resulting mixture was refluxed for 50 minutes, allowed to cool to ambient temperature and poured into aqueous saturated sodium bicarbonate solution (50 ml). The separated oil was extracted with ethyl acetate. The organic layer was washed successively with dilute aqueous hydrochloric acid, aqueous sodium bicarbonate solution and brine. The solvent was dried and evaporated in vacuo. The residue was purified by columnchromatography on silica gel (elution by chloroform/n-hexane, 1/10-1/6) to give 2,2-dibutyl-3,4-dihydro-5-methoxy-1 (2H)-naphthalenone (255 mg) as a pale yellow syrup.

1. temperatureThe resulting mixture was refluxed for 50 minutes
2. temperatureto cool to ambient temperature
3. extractionThe separated oil was extracted with ethyl acetate
4. washThe organic layer was washed successively with dilute aqueous hydrochloric acid, aqueous sodium bicarbonate solution and brine
5. customThe solvent was dried
6. customevaporated in vacuo
7. customThe residue was purified by columnchromatography on silica gel (elution by chloroform/n-hexane, 1/10-1/6)

ORD record

ord-0bf9eafdae3d44699760042e7218d12d

Source dataset

uspto-grants-1991_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05061718