2-Chloro-1,4-naphthoquinone → 2-Chloro-3-(4-methoxycyclohexyl)-1,4-naphthoquinone

HRID 1682179Notes

Reaction equation

HRID 1682179 reaction equation
[Cl:1][C:2]1[C:3](=[O:13])[C:4]2[C:9]([C:10](=[O:12])[CH:11]=1)=[CH:8][CH:7]=[CH:6][CH:5]=2.[CH3:14][O:15][CH:16]1[CH2:21][CH2:20][CH:19](C(O)=O)[CH2:18][CH2:17]1.S1(CCCC1)(=O)=O.S(OOS([O-])(=O)=O)([O-])(=O)=O.[NH4+].[NH4+]>C(#N)C.O.[N+]([O-])([O-])=O.[Ag+]>[Cl:1][C:2]1[C:3](=[O:13])[C:4]2[C:9]([C:10](=[O:12])[C:11]=1[CH:19]1[CH2:20][CH2:21][CH:16]([O:15][CH3:14])[CH2:17][CH2:18]1)=[CH:8][CH:7]=[CH:6][CH:5]=2

Participants

8

Reactant 4

HCID 138912-Chloro-1,4-naphthoquinoneHCID 31347SulfolaneHCID 62648Ammonium PersulfateHCID 736153Rac-(1r,4r)-4-methoxycyclohexane-1-carboxylic acid

Product 1

HCID 198048602-Chloro-3-(4-methoxycyclohexyl)-1,4-naphthoquinone

Reagents, catalysts & solvents 3

HCID 24470Silver NitrateCatalystHCID 962WaterSolvent2×HCID 6342AcetonitrileSolvent

Conditions

Temperature
65 °C

Procedure

A mixture of 2-chloro-1,4-naphthoquinone (1.16 g), 4-methoxycyclohexane-1-carboxylic acid (1.3 g) and silver nitrate (0.3 g) were stirred at 65° C. in a mixture of acetonitrile (2.5 ml), sulpholane (7.5 ml) and water (17.5 ml) while a solution of ammonium persulphate (2.3 g) in water (5 ml) was added dropwise during 15 minutes. The reaction mixture was stirred for a further 15 minutes at 65° C., cooled in ice and extracted with ether. The ether extracts were washed with sodium bicarbonate solution, dried and evaporated. The crude product was recrystallised from acetonitrile to yield 2-chloro-3-(4-methoxycyclohexyl)-1,4-naphthoquinone, m.p. 110°-113° C.; the product so obtained (0.9 g) was dissolved in boiling methanol (25 ml) and a solution of potassium hydroxide (0.9 g) in water (9 ml) added dropwise during 10 minutes. The reaction mixture was then refluxed for a further 30 minutes, concentrated hydrochloric acid (5 ml) added dropwise and the mixture cooled in ice. Addition of an equal volume of water precipitated an oil which slowly turned to a semi-solid. Recrystallisation from acetonitrile yielded 2-hydroxy-3-(4-methoxycyclohexyl)-1,4-naphthoquinone, m.p. 152°-155°, shown by n.m.r to be the pure trans isomer.

Workup

  1. additionwas added dropwise during 15 minutes
  2. temperaturecooled in ice
  3. extractionextracted with ether
  4. washThe ether extracts were washed with sodium bicarbonate solution
  5. customdried
  6. customevaporated
  7. customThe crude product was recrystallised from acetonitrile

Sources & evidence

ORD record
ord-be338a6e69c54d0d81334beb25cf98c8
Source dataset
uspto-grants-1992_12
Patent number
US05175319

Reaction notes

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