Pyridine → Flavanone

HRID 2054549Notes

Reaction equation

HRID 2054549 reaction equation
[C:1]([C:4]1[CH:13]=[C:12]([O:14][CH3:15])[C:11]2[C:6](=[CH:7][CH:8]=[CH:9][CH:10]=2)C=1O)(=O)[CH3:2].C[O:18]C1C=C(C=C(OC)C=1OC)C=O.N1CC[CH2:34][CH2:33][CH2:32]1.N1C=CC=CC=1>C(O)C>[O:14]1[C:15]2[C:1](=[CH:2][CH:32]=[CH:33][CH:34]=2)[C:4](=[O:18])[CH2:13][CH:12]1[C:11]1[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=1

Participants

6

Reactant 4

HCID 1049PyridineHCID 68583,4,5-TrimethoxybenzaldehydeHCID 8082PiperidineHCID 109000401-(1-Hydroxy-4-methoxynaphthalen-2-yl)ethan-1-one

Product 1

HCID 10251FlavanoneYield 45%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A solution of the acetonaphthone 12 (1.08 g, 5 mmol) and trimethoxybenzaldehyde (2) (1.08 g, 5.5 mmol) in ethanol (25 mL) was treated with piperidine (3 mL) and pyridine (3 mL) and refluxed for 24 h. On cooling, the product, 13 precipitated out of solution and was collected by filtration and washed with ethanol to yield 488 mg of 13 as the first crop. The filtrate was further purified by flash chromatography and the product eluted with hexanes/CH2Cl2/EtOAc (6:3:1) to give a light orange solid, which was recrystallized from ethanol to afford an additional 399 mg of a second crop. Combined yield 45%. 1H NMR (300 MHz, CDCl3): δ 2.99 (m, 1H, 3-H), 3.19 (m, 1H, 3-H), 3.91, 3.93, 4.03 (3s, 12H, OCH3), 5.57 (m, 1H, 2-H), 6.80 (s, 2H, 2′,6′-Ar—H), 7.18 (s, 1H, Ar-5-H) 7.57 (m, 1H, Ar—H), 8.26 (d, 1H, Ar—H), 8.33 (d, 1H, Ar—H).

Workup

  1. temperaturerefluxed for 24 h
  2. temperatureOn cooling
  3. customthe product, 13 precipitated out of solution
  4. filtrationwas collected by filtration
  5. washwashed with ethanol

Sources & evidence

ORD record
ord-6ffc7637d5ed4a4b91cc1d9b4595318b
Source dataset
uspto-grants-2008_02
Patent number
US07329687B2

Reaction notes

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