Piperidine → Benzoic Acid

HRID 468688Notes

Reaction equation

HRID 468688 reaction equation
N1CCCCC1.FC(F)OC1C=CC(C=O)=CC=1OC.C(CC(N[C:28]1[CH:36]=[CH:35][CH:34]=[CH:33][C:29]=1[C:30]([OH:32])=[O:31])=O)(O)=O>C1(C)C=CC=CC=1>[C:30]([OH:32])(=[O:31])[C:29]1[CH:33]=[CH:34][CH:35]=[CH:36][CH:28]=1

Participants

5

Reactant 3

HCID 8082PiperidineHCID 4399222-(2-Carboxyacetamido)benzoic acidHCID 31612494-(Difluoromethoxy)-3-methoxybenzaldehyde

Product 1

HCID 243Benzoic AcidYield 81.6%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

Piperidine (0.25 mL, 2.6 mmol) was added to a suspension of 4-(difluoromethoxy)-3-methoxybenzaldehyde (0.52 g, 2.6 mmol) and 2-[(carboxyacetyl)amino]benzoic acid (0.52 mg, 2.6 mmol) in toluene (5.0 mL). The reaction flask was fitted with a Dean-Stark apparatus and heated to reflux for 30 min. The reaction was then cooled to rt and the resulting suspension was filtered and washed with toluene. The piperidinium salt was dissolved in MeOH (5 mL) and water (2 mL) and the solution was acidified with 50% aqueous AcOH. The crude product was collected by filtration and recrystallised from EtOH/water, filtered and washed with water to afford (E)-2-[[3-methoxy-4-(difluoromethoxy)phenyl)-1-oxo-2-propenyl]amino]benzoic acid (259 mg, 71%) as a colourless crystalline solid; mp 172-174° C.; δH (500 MHz, DMSO-d6) 3.90 (s, 3H, OCH3), 6.94 (d, J=15.6 Hz, 1H, CH═CHCO), 7.12 (t, J=75 Hz, 1H, OCHF2), 7.17 (t, J3,4=J4,5=8.0 Hz, 1H, H4), 7.20 (d, J5′,6′=8.0 Hz, 1H, H5′), 7.32 (dd, J5′,6′=8.0, J2′,6′=2.0 Hz, 1H, H6′), 7.56 (d, J2′,6′=2.0 Hz, 1H, H2′), 7.61 (d, J=15.6 Hz, 1H, CH═CHCO), 7.62 (dt, J4,5=J5,6=8.0, J3,5=1.5 Hz, 1H, H5), 8.00 (dd, J3,4=8.0, J3,5=1.5 Hz, 1H, H3), 8.61 (d, J5,6=8.0 Hz, 1H, H6), 11.33 (s, 1H, NH), 13.60 (br s, 1H, CO2H); δC (125 MHz, DMSO-d6) 56.1, 112.3, 114.5, 116.5 (t, J=256 Hz), 116.8, 120.4, 120.8, 121.4, 122.7, 122.9, 131.1, 132.9, 134.0, 140.6, 140.8, 150.7, 163.7, 169.4; HRMS (ESI−) calculated for C18H15F2NO5 [M-H ]− 362.0835, found 362.0839; νmax 1032, 1260, 1586, 1604, 1661, 2988, 3509 cm−1.

Workup

  1. customThe reaction flask was fitted with a Dean-Stark apparatus
  2. temperatureheated
  3. temperatureto reflux for 30 min
  4. filtrationthe resulting suspension was filtered
  5. washwashed with toluene
  6. dissolutionThe piperidinium salt was dissolved in MeOH (5 mL)
  7. filtrationThe crude product was collected by filtration
  8. customrecrystallised from EtOH/water
  9. filtrationfiltered
  10. washwashed with water

Sources & evidence

ORD record
ord-3c7546540e5c46a69b95b705d283bfdd
Source dataset
uspto-grants-2014_01
Patent number
US08624056B2

Reaction notes

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