Hydrochloric Acid → N-(mesityl)-3-(2-hydroxyphenyl)-4,5-dihydro-imidazolium chloride

HRID 11737Notes

Reaction equation

HRID 11737 reaction equation
[C:1]1([CH3:22])[CH:6]=[C:5]([CH3:7])[CH:4]=[C:3]([CH3:8])[C:2]=1[NH:9][C:10](=O)[C:11]([NH:13][C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][C:15]=1[OH:20])=O.B.[CH2:24]1COCC1.[ClH:29]>CO>[Cl-:29].[C:1]1([CH3:22])[CH:6]=[C:5]([CH3:7])[CH:4]=[C:3]([CH3:8])[C:2]=1[N+:9]1[CH2:10][CH2:11][N:13]([C:14]2[CH:19]=[CH:18][CH:17]=[CH:16][C:15]=2[OH:20])[CH:24]=1

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 2723981Borane;tetrahydrofuranHCID 21976144N-(mesityl)-N'-(2-hydroxyphenyl)-oxalamide

Product 1

HCID 68532559N-(mesityl)-3-(2-hydroxyphenyl)-4,5-dihydro-imidazolium chlorideYield 55%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

N-(Mesityl)-N′-(2-hydroxyphenyl)-oxalamide (1.47 g, 4.9 mmol, 1 eq), prepared according to the synthesis method described in Example 3, was weighed into an oven-dried round-bottom flask. To this was added BH3-THF (1M in THF) (39 ml, 39.2 mmol, 8 eq). A great deal of bubbling resulted, as the solution turned bright orange. The solution was allowed to reflux overnight. The next day, the solution was observed to have turned clear. The solution was then allowed to cool to room temperature. Methanol was then very slowly added to the solution until all bubbling ceased. Concentrated HCl solution (1.5 ml) was then added, and the solvent was removed under reduced pressure. The resulting solid was dissolved in methanol, and then the solvent was again removed under reduced pressure. This process was repeated twice more. In this way, the remaining boron was removed as B(OMe)3. Triethylorthoformate (15 ml) was then added to the resulting solid, forming a suspension. The suspension was then heated to 100° C. As the suspension was heated, the solid was observed to slowly go into solution. After aproximately one minute at high temperature, a white solid precipitated. It was allowed to stir for five more minutes, and was then filtered. The resulting solid was washed with ether, to provide the desired product as a white powder (0.854 g, 2.7 mmol, 55% yield). 1H NMR (300 MHz, CDCl3) δ 11.43 (s, 1H), 8.84 (s, 1H), 7.54 (dd, J=8.25, 1.2 Hz, 1H), 7.05 (dd, J=8.0, 1.2 Hz, 1H), 6.92 (m, 2H), 6.73 (dt, J=7.7, 0.9 Hz 1H), 4.80 (t, J=11.4 Hz, 2H), 4.37 (t, J=11.7 Hz, 2H), 2.33 (s, 3H), 2.29 (s, 6H); 13C NMR (75 MHz, CDCl3) δ 157.4, 150.0, 141.0, 135.3, 130.7, 130.3, 128.8, 122.8, 120.4, 119.9, 118.8, 51.0, 50.4, 21.3, 18.2. Anal. Calcd for C18H21ClN2O: C, 68.24; H, 6.68; N, 8.84. Found: C, 67.86; H, 6.92; N, 8.52.

Workup

  1. customaccording to the synthesis method
  2. customwas weighed into an oven-dried round-bottom flask
  3. customA great deal of bubbling
  4. customresulted, as the solution
  5. temperatureto reflux overnight
  6. customthe solvent was removed under reduced pressure
  7. dissolutionThe resulting solid was dissolved in methanol
  8. customthe solvent was again removed under reduced pressure
  9. customIn this way, the remaining boron was removed as B(OMe)3
  10. additionTriethylorthoformate (15 ml) was then added to the resulting solid
  11. customforming a suspension
  12. temperatureThe suspension was then heated to 100° C
  13. temperatureAs the suspension was heated
  14. customa white solid precipitated
  15. filtrationwas then filtered
  16. washThe resulting solid was washed with ether

Sources & evidence

ORD record
ord-e7ffc9e7c0c24fb7896f205b97f7c3e5
Source dataset
uspto-grants-2006_08
Patent number
US07098278B2

Reaction notes

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