Hydroxyamine hydrochloride → 5,6-Dihydrobenz(h)quinoline

HRID 1910344Notes

Reaction equation

HRID 1910344 reaction equation
Cl.[NH2:2]O.C(O[CH:7]1[CH:16](C)[CH2:15][C:14]2[CH2:13][CH2:12][C:11]3[CH:18]=[CH:19][CH:20]=[CH:21][C:10]=3[C:9]=2O1)C>C(#N)C>[N:2]1[C:9]2[C:10]3[CH:21]=[CH:20][CH:19]=[CH:18][C:11]=3[CH2:12][CH2:13][C:14]=2[CH:15]=[CH:16][CH:7]=1

Participants

4

Reactant 2

HCID 443297Hydroxyamine hydrochlorideHCID 592948342-Ethoxy-3-methyl-3,4,5,6-tetrahydrobenzo[h]chromene

Product 1

HCID 122265145,6-Dihydrobenz(h)quinolineYield 48.3%

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

To a suspension of hydroxylamine hydrochloride (46.1 g, 0.663 mol) in 1070 mL of acetonitrile was added 2-ethoxy-3-methyl-3,4,5,6-tetrahydrobenzo[h]chromene (140 g, 0.265 mol) from step two. The reaction mixture was heated at reflux under nitrogen with stirring for 16 h. Evaporation of the acetonitrile, followed by vacuum distillation of the product yielded 34.5 g of a crude product that was further purified by silica gel chromatography with 5/95 ethyl acetate/hexane as the eluent, yielding 23.2 g (45%) of 5,6-dihydrobenzo[h]quinoline as a yellow liquid.

Workup

  1. temperatureThe reaction mixture was heated
  2. temperatureat reflux under nitrogen
  3. customEvaporation of the acetonitrile
  4. distillationfollowed by vacuum distillation of the product
  5. customyielded 34.5 g of a crude product that
  6. customwas further purified by silica gel chromatography with 5/95 ethyl acetate/hexane as the eluent

Sources & evidence

ORD record
ord-cb896bd978d4455e8dcbf87e755285f5
Source dataset
uspto-grants-2013_12
Patent number
US08603645B2

Reaction notes

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