Benzaldehyde → 8-Benzylidene-2-(2-phenylethenyl)-5,6,7,8-tetrahydroquinoline

HRID 2085007Notes

Reaction equation

HRID 2085007 reaction equation
[NH:1]1[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=2)[CH2:4][CH2:3][CH2:2]1.[C:11]1([CH:17]=O)[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1>>[CH:17](=[C:9]1[C:10]2[N:1]=[C:2]([CH:3]=[CH:4][C:5]3[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=3)[CH:3]=[CH:4][C:5]=2[CH2:6][CH2:7][CH2:8]1)[C:11]1[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1

Participants

3

Reactant 2

HCID 240BenzaldehydeHCID 694601,2,3,4-Tetrahydroquinoline

Product 1

HCID 688930318-Benzylidene-2-(2-phenylethenyl)-5,6,7,8-tetrahydroquinolineYield 197.8%

Conditions

Temperature
165 °C

Procedure

A 1 L round-bottomed flask equipped with a stirring bar, condenser and nitrogen gas inlet was charged with 2-methyl-5,6,7,8-tetrahydroquinoline (2, 80.5 g, 0.547 mol), PhCHO (222 mL, 2.19 mol), and Ac20 (206 mL, 2.19 mol). The mixture was heated under reflux at 160-170° C. under nitrogen atmosphere for 5 days. Then all volatile materials were removed by distillation under atmospheric pressure at ˜170° C. The residue was mixed with hot EtOH (200 mL) and stirred at 70° C. The stirred solution was cooled to room temperature and seeded with crystals of the product 3 to facilitate crystallization. The precipitate was collected by vacuum filtration, washed with EtOH (100 mL) and dried in vacuo to give the pale brown solid (175 g), which was impure. The crude material was chromatographed over silica gel (hexane only) to give bisbenzylidene 3 (142.4 g, 83%) as a pale yellow solid. Physical data see A. B. Khasanov's Ph. D. Thesis (2000).

Workup

  1. customA 1 L round-bottomed flask equipped with a stirring bar, condenser and nitrogen gas inlet
  2. temperatureThe mixture was heated
  3. customThen all volatile materials were removed by distillation under atmospheric pressure at ˜170° C
  4. additionThe residue was mixed with hot EtOH (200 mL)
  5. temperatureThe stirred solution was cooled to room temperature
  6. customcrystallization
  7. filtrationThe precipitate was collected by vacuum filtration
  8. washwashed with EtOH (100 mL)
  9. customdried in vacuo

Sources & evidence

ORD record
ord-3b565ee6ef3b46d9859d2a3412acf6b1
Source dataset
uspto-grants-2004_04
Patent number
US06720188B2

Reaction notes

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