Sodium Hydroxide → 3-Methyl-5,6,7,8-tetrahydroquinoline

HRID 2083420Notes

Reaction equation

HRID 2083420 reaction equation
COC([CH:5]1[C:14]2[N:13]=[CH:12][C:11]([CH3:15])=[CH:10][C:9]=2[CH2:8][CH2:7][CH2:6]1)=O.[OH-].[Na+]>>[CH3:15][C:11]1[CH:12]=[N:13][C:14]2[CH2:5][CH2:6][CH2:7][CH2:8][C:9]=2[CH:10]=1

Participants

3

Reactant 2

HCID 14798Sodium HydroxideHCID 122789608-Quinolinecarboxylic acid, 5,6,7,8-tetrahydro-3-methyl-, methyl ester

Product 1

HCID 1200283-Methyl-5,6,7,8-tetrahydroquinoline

Procedure

A solution of 15 % n-butyl lithium in hexane (51 ml. ca. 0.12 m) was added portionwise to a solution of 3-methyl-5,6,7,8-tetrahydroquinoline (14.7 g., 0.1 m) in ether (100 ml.) and the mixture allowed to stand at room temperature for 1 hour and then added dropwise to a cooled, stirred solution of methylchloroformate (9.45 g., 0.1 m) in ether (100 ml.). The mixture was stirred at 50° C for 1 hour. The reaction mixture was diluted with water (20 ml.) and then treated with 2N HCl until acidic. The ethereal solution was separated and washed with 2N HCl (2 × 25 ml.). The combined aqueous washings were extracted with ether and the ethereal extracts discarded. The aqueous solution was adjusted to pH 9.0 with Na2C03 and extracted with chloroform (3 × 50 ml.) and the combined extracts dried and evaporated to give a pale yellow oil (16 g) which on GLC examination (3% SE30) showed a mixture of unreacted tetrahydroquinoline (45%), the title compound (23%) and the 8,8-dicarboxylic ester (20%). The mixture was treated with 10% sodium hydroxide (75 ml.). and heated at reflux with stirring for 4 hours, cooled and extracted with ether (3 × 50 ml.). The combined ethereal extracts were dried, evaporated and distilled to give unreacted 3-methyl-5,6,7,8-tetrahydroquinoline (7 g.) b.p. 116°/18 mm Hg. The basic solution was adjusted to pH 8.5-9.0 with concentrated HC1 and evaporated to dryness and the residue treated with methanol previously saturated with dry HCl (50 ml.) and allowed to stand at room temperature for 5 hours. The solvent was removed and the residue dissolved in water (20 ml.) and extracted with ether (2 × 50 ml.). The aqueous solution was adjusted to pH 9.0 with Na2CO3 and extracted with chloroform (3 × 25 ml.) and the combined extracts dried and evaporated to give the title compound (3 gm.).

Workup

  1. temperatureand heated
  2. temperatureat reflux
  3. temperaturecooled
  4. extractionextracted with ether (3 × 50 ml.)
  5. customThe combined ethereal extracts were dried
  6. customevaporated
  7. distillationdistilled

Sources & evidence

ORD record
ord-f120d5971d5140c1819e984c6c8a8f73
Source dataset
uspto-grants-1978_04
Patent number
US04085215

Reaction notes

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