Pyridine → Flavanone

HRID 1869562Notes

Reaction equation

HRID 1869562 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), 7.65 (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-60e02c57890c49cea3814dc82e28c926
Source dataset
uspto-grants-2009_12
Patent number
US07638554B2

Reaction notes

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