Hydrochloric Acid → 5,6,7,8-Tetrahydro-3-methyl-8-quinolinecarbothioamide

HRID 1974024Notes

Reaction equation

HRID 1974024 reaction equation
[CH3:1][C:2]1[CH:3]=[N:4][C:5]2[CH2:6][CH2:7][CH2:8][CH2:9][C:10]=2[CH:11]=1.C([Mg]Br)(C)C.C[Si]([N:21]=[C:22]=[S:23])(C)C.Cl>C1(C)C=CC=CC=1.O>[CH3:1][C:2]1[CH:3]=[N:4][C:5]2[CH:6]([C:22](=[S:23])[NH2:21])[CH2:7][CH2:8][CH2:9][C:10]=2[CH:11]=1

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 75297IsothiocyanatotrimethylsilaneHCID 1200283-Methyl-5,6,7,8-tetrahydroquinoline2×HCID 178418365HCID 178418365, compound

Product 1

HCID 30039215,6,7,8-Tetrahydro-3-methyl-8-quinolinecarbothioamideYield 5%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 1140TolueneSolvent

Procedure

3-Methyl-5,6,7,8-tetrahydroquinoline (7.3g, 0.05 mol.) was added to a solution of isopropylmagnesium bromide [prepared from isopropylbromide (6.15g, 0.05 mol), magnesium (1.44g, 0.06 mol) in ether (10 ml.)] and the solution heated at 60° to remove the ether by distillation. Toluene (5 ml.) was added and the reaction mixture was heated at 120° for 2 hours, cooled, diluted with toluene (30 ml) and this solution was added to a solution of trimethylsilyl isothiocyanate (7.85 g, 0.06 mol) in toluene (50 ml.) at 0° C. The reaction mixture was stirred at room temperature for 12 hours, diluted with water (15 ml.) and the pH adjusted to 2.0 with Conc. HCl. The aqueous solution was extracted with ether and the extracts discarded. The aqueous solution was adjusted to pH 9.0 with Na2CO3 and extracted with chloroform (3 × 50 ml.). The combined extracts were washed with brine, dried and the solvent removed to give a mixture of 3-methyl-5,6,7,8-tetrahydroquinoline and the title compound (5%) which was isolated by chromatography and identified by comparison with authentic material.

Workup

  1. temperaturethe solution heated at 60°
  2. customto remove the ether
  3. distillationby distillation
  4. additionToluene (5 ml.) was added
  5. temperaturethe reaction mixture was heated at 120° for 2 hours
  6. temperaturecooled
  7. additiondiluted with toluene (30 ml)
  8. extractionThe aqueous solution was extracted with ether
  9. extractionextracted with chloroform (3 × 50 ml.)
  10. washThe combined extracts were washed with brine
  11. customdried
  12. customthe solvent removed
  13. customto give

Sources & evidence

ORD record
ord-c65e54a06ddb4d0ea2d89f82cd1787a7
Source dataset
uspto-grants-1976_12
Patent number
US04000142

Reaction notes

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