Hydrochloric Acid → 2-Cyano-8-methoxy-3,4-dihydronaphthalene

HRID 654232Notes

Reaction equation

HRID 654232 reaction equation
[C-:1]#[N:2].[CH3:3][O:4][C:5]1[CH:6]=[CH:7][CH:8]=[C:9]2[C:14]=1[CH2:13][C:12](=O)[CH2:11][CH2:10]2.Cl>[I-].[Zn+2].[I-].C(#N)C>[C:1]([C:12]1[CH2:11][CH2:10][C:9]2[C:14](=[C:5]([O:4][CH3:3])[CH:6]=[CH:7][CH:8]=2)[CH:13]=1)#[N:2]

Participants

6

Reactant 3

HCID 313Hydrochloric AcidHCID 5975CyanideHCID 41360218-Methoxy-2-tetralone

Product 1

HCID 157185932-Cyano-8-methoxy-3,4-dihydronaphthaleneYield 64.8%

Reagents, catalysts & solvents 2

HCID 9883512zinc(II)iodideCatalystHCID 6342AcetonitrileSolvent

Conditions

Temperature
120 °C

Procedure

Trimethylsylyl cyanide (6.9 g, 9.3 ml, 0.07 mol) is added dropwise in 10 minutes to a mixture of 8-methoxy-3,4-di-hydronaphthalen-2(1H)-one (10.9 g, 0.06 mol) prepared as described in the literature (J. Chem. Soc., 1958, 409), anhydrous acetonitrile (60 ml) and a catalytic amount of zinc iodide under nitrogen atmosphere and the obtained mixture is heated to 80° C. ext. for 3 hours. The reaction mixture is cooled, 1N HCl (20 ml) is slowly added thereto and stirring is continued for 2 hours at room temperature. The solvent is then evaporated off under vacuum, the residue is taken up in ethyl acetate, and the organic solution is washed with water, dried over sodium sulfate, filtered and evaporated to dryness. The obtained product is triturated with petroleum ether, filtered and dissolved in pyridine (100 ml). POCl3 (20 ml) is added dropwise in 10 minutes and the obtained mixture is heated to 120° C. ext. for 3 hours. The reaction mixture is then poured into ice, made acidic by the addition of concentrated hydrochloric acid and extracted with ethyl ether. The organic phase is washed with water, dried and evaporated to dryness and the obtained residue is crystallised from isopropyl ether yielding 2-cyano-8-methoxy-3,4-dihydronaphthalene (7.2 g); m.p. 66°-68° C.

Workup

  1. customprepared
  2. temperatureThe reaction mixture is cooled
  3. waitis continued for 2 hours at room temperature
  4. customThe solvent is then evaporated off under vacuum
  5. washthe organic solution is washed with water
  6. dry with materialdried over sodium sulfate
  7. filtrationfiltered
  8. customevaporated to dryness
  9. customThe obtained product is triturated with petroleum ether
  10. filtrationfiltered
  11. dissolutiondissolved in pyridine (100 ml)
  12. additionPOCl3 (20 ml) is added dropwise in 10 minutes
  13. waitfor 3 hours
  14. additionThe reaction mixture is then poured into ice
  15. additionmade acidic by the addition of concentrated hydrochloric acid
  16. extractionextracted with ethyl ether
  17. washThe organic phase is washed with water
  18. customdried
  19. customevaporated to dryness
  20. customthe obtained residue is crystallised from isopropyl ether

Sources & evidence

ORD record
ord-eb87406b5d664240b2f2182e3b410b09
Source dataset
uspto-grants-1992_07
Patent number
US05130339

Reaction notes

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