Water → 5,8-Dihydro-2-methyl 1,4-naphthoquinone

In toluene (30 ml) and acetic acid (5 ml), were dissolved 7.0 g (0,057 mol) of toluquinone, to which 7.6 g (0.14 mol) of 1,3-butadiene were added at -10° C. under stirring. Thereafter, the resultant mixture was gradually heated and stirred further for 3 hours at 40° C. The liquid reaction mixture was washed with water, and an organic layer was dried and concentrated under reduced pressure. Concentrated hydrochloric acid (1 ml) and ethanol (50 ml) were added to the residue, and the mixture was stirred for 1 hour at 40° C. After the liquid reaction mixture was concentrated under reduced pressure, the residue was dissolved in a liquid mixture of toluene (50 ml), n-propanol (25 ml) and water (25 ml). To the solution, were added 1.0 g (0.23 mol) of lithium chloride, 5.0 g (0.29 mol) of cupric chloride dihydrate to stir the resultant mixture for 1 hour at 40° C. The liquid reaction mixture was poured into water (100 ml) to make extraction with toluene (50 ml × 2). The resulting organic layer was washed with water, dried and concentrated under reduced pressure to obtain a crude product of the title compound. This crude product was recrystallized from methanol (20 ml) to obtain 9.14 g of the title compound as yellow crystals (yield: 92%).

1. stirringstirred further for 3 hours at 40° C
2. customThe liquid reaction mixture
3. washwas washed with water
4. customan organic layer was dried
5. concentrationconcentrated under reduced pressure
6. additionConcentrated hydrochloric acid (1 ml) and ethanol (50 ml) were added to the residue
7. stirringthe mixture was stirred for 1 hour at 40° C
8. customAfter the liquid reaction mixture
9. concentrationwas concentrated under reduced pressure
10. dissolutionthe residue was dissolved in a liquid mixture of toluene (50 ml), n-propanol (25 ml) and water (25 ml)
11. customThe liquid reaction mixture
12. extractionextraction with toluene (50 ml × 2)
13. washThe resulting organic layer was washed with water
14. customdried
15. concentrationconcentrated under reduced pressure

ORDレコード

ord-bd6a48f4d00c4bdb971168e509fefa7b

出典データセット

uspto-grants-1995_05

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US05412124