Boron tribromide → 3-(1-Ethyl-4,4,6-trimethyl-2-oxo-1,2,3,4-tetrahydro-quinolin-7-yl)-4-hydroxy-benzaldehyde

HRID 883066Notes

Reaction equation

HRID 883066 reaction equation
[CH2:1]([N:3]1[C:12]2[C:7](=[CH:8][C:9]([CH3:23])=[C:10]([C:13]3[CH:14]=[C:15]([CH:18]=[CH:19][C:20]=3[O:21]C)[CH:16]=[O:17])[CH:11]=2)[C:6]([CH3:25])([CH3:24])[CH2:5][C:4]1=[O:26])[CH3:2].B(Br)(Br)Br>ClCCl>[CH2:1]([N:3]1[C:12]2[C:7](=[CH:8][C:9]([CH3:23])=[C:10]([C:13]3[CH:14]=[C:15]([CH:18]=[CH:19][C:20]=3[OH:21])[CH:16]=[O:17])[CH:11]=2)[C:6]([CH3:25])([CH3:24])[CH2:5][C:4]1=[O:26])[CH3:2]

Participants

4

Reactant 2

HCID 25134Boron tribromide2×HCID 866117603-(1-Ethyl-4,4,6-trimethyl-2-oxo-1,2,3,4-tetrahydro-quinolin-7-yl)-4-methoxy-benzaldehyde

Product 1

HCID 866117613-(1-Ethyl-4,4,6-trimethyl-2-oxo-1,2,3,4-tetrahydro-quinolin-7-yl)-4-hydroxy-benzaldehydeYield 53.1%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent3×

Procedure

A solution of 7.05 g of Compound 1B (20.1 mmol) in 60 mL of dry dichloromethane was treated with 40 mL of 1M BBr3 in dichloromethane. The reaction flask was then equipped with a reflux condenser, nitrogen inlet and heated to reflux. After 2 hours another 20 mL of BBr3 was added and refluxing continued for an additional 2 hours. The reaction mixture was allowed to cool to room temperature. The crude reaction mixture was diluted with dichloromethane and washed with water (2×50 mL) and brine (50 ml), dried over magnesium sulfate, filtered and excess solvent removed on the rotary evaporator. The crude product Compound 1C was purified by flash chromatography (EtOAc/Hexanes; gradient 15% to 30%) to give 3.6 g (53%) of product as a white solid. MS (electrospray): mass calculated for C21H23NO3, 337.17; m/z found 338.3, [M+H]+. 1HNMR (400 MHz, CDCl3): 9.91 (s, 1H), 7.85 (dd, J=2.0, 8.5 Hz, 1H), 7.70 (d, J=1.98 Hz, 1H), 7.25 (s, 1H), 7.15 (d, J=8.4 Hz, 1H), 6.89 (s, 1H), 6.20 (s, 1H), 4.01 (q, J=7.1 Hz, 2H), 2.52 (s, 2H), 2.15 (s, 3H), 1.33 (s, 6H), 1.22 (t, J=7.09 Hz, 3H).

Workup

  1. customThe reaction flask was then equipped with a reflux condenser, nitrogen inlet
  2. temperatureheated to reflux
  3. temperaturerefluxing
  4. customThe crude reaction mixture
  5. washwashed with water (2×50 mL) and brine (50 ml)
  6. dry with materialdried over magnesium sulfate
  7. filtrationfiltered
  8. customexcess solvent removed on the rotary evaporator
  9. customThe crude product Compound 1C was purified by flash chromatography (EtOAc/Hexanes; gradient 15% to 30%)

Sources & evidence

ORD record
ord-6c0208a80f9742ea994af1ae07a0da57
Source dataset
uspto-grants-2012_08
Patent number
US08236819B2

Reaction notes

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