Hydrochloric Acid → 3-Methyl-5,6,7,8-tetrahydroquinoline-8-carboxamide

HRID 1974021Notes

Reaction equation

HRID 1974021 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([Li])CCC.C[Si]([N:21]=[C:22]=[O:23])(C)C.Cl>CCCCCC.O>[CH3:1][C:2]1[CH:3]=[N:4][C:5]2[CH:6]([C:22]([NH2:21])=[O:23])[CH2:7][CH2:8][CH2:9][C:10]=2[CH:11]=1

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 70696Trimethylsilyl isocyanateHCID 1200283-Methyl-5,6,7,8-tetrahydroquinolineHCID 178418339Butyllithium

Product 1

HCID 122782273-Methyl-5,6,7,8-tetrahydroquinoline-8-carboxamideYield 35%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 8058HexaneSolvent3×

Procedure

A solution of 3-methyl-5,6,7,8-tetrahydroquinoline (7.3 g., 0.05 mol.) in hexane (50 ml.) was cooled to 0° C and treated dropwise with 15w/w butyllithium in hexane (26 ml., 0.06 mol.) in a nitrogen atmosphere. The reaction mixture was allowed to stand at 0° C for 1 hour and was then added dropwise over 30 minutes to a solution of trimethylsilylisocyanate (19.5 g., 0.17 mol.) in hexane (50 ml.) keeping the internal temperature at -20° C. The reaction mixture was allowed to stand at -20° C for 1 hour and was then diluted with water (50 ml.) and the pH adjusted to 2.0 with conc. HCl. The hexane layer was separated and discarded and the aqueous solution adjusted to pH 10.0 with sodium carbonate and extracted with chloroform (3 × 25 ml.). The combined extracts were washed with saturated brine, dried and the solvent removed in vacuo. The residue was triturated with n-hexane, filtered and the solid crystallised from ethyl acetate to give the title compound as colourless needles (3.1 g., 35%) m.p. 104° C. identical in all respects to the authentic material (when crystallised from ethyl acetate). Analysis: Found C, 69.1; 7.4; N, 14.7. C11H14N2O requires C, 69.5; H, 7.4; N, 14.7. The hexane soluble material was distilled to give recovered 3-methyl-5,6,7,8-tetrahydroquinoline (4.2 g.) b.p. 120°/15 mm.

Workup

  1. customat -20° C
  2. waitto stand at -20° C for 1 hour
  3. customThe hexane layer was separated
  4. extractionextracted with chloroform (3 × 25 ml.)
  5. washThe combined extracts were washed with saturated brine
  6. customdried
  7. customthe solvent removed in vacuo
  8. customThe residue was triturated with n-hexane
  9. filtrationfiltered
  10. customthe solid crystallised from ethyl acetate

Sources & evidence

ORD record
ord-3bb1e0a90907410ca52ac97718e0a043
Source dataset
uspto-grants-1976_12
Patent number
US04000142

Reaction notes

Loading…