Methanol → N-Diphenylmethylene-4-bromoaniline

HRID 1978243Notes

Reaction equation

HRID 1978243 reaction equation
[C:1]([C:9]1[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=1)(=O)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[Br:15][C:16]1[CH:22]=[CH:21][C:19]([NH2:20])=[CH:18][CH:17]=1.CO>C1(C)C=CC=CC=1>[C:2]1([C:1]([C:9]2[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=2)=[N:20][C:19]2[CH:21]=[CH:22][C:16]([Br:15])=[CH:17][CH:18]=2)[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

5

Reactant 3

HCID 887MethanolHCID 3102BenzophenoneHCID 78074-Bromoaniline

Product 1

HCID 11013110N-Diphenylmethylene-4-bromoaniline

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

The method of Taguchi and Westheimer1 was modified as follows: benzophenone (455 g, 2.50 mol) and 4-bromoaniline (473 g, 2.75 mol) were dissolved in toluene (1.2 L) under argon in a 5 L flask containing activated molecular sieves (5 Å, 1.25 kg). The flask was fitted with a reflux condenser, rubber septum, and pressure outlet. The mixture was heated to gentle reflux and shaken occasionally; an intense yellow color soon developed. After 18 h, heating was discontinued and the solution was cooled to rt. The solution was decanted from the molecular sieves, and the sieves were washed with Et2O until the filtrate was colorless. The combined organic solutions were concentrated in vacuo to give an orange oil. MeOH (ca. 80 mL) and a seed crystal of 1 were added. The product was allowed to crystallize at 0° C. and the precipitate was collected by filtration. The mother liquor was further concentrated, and a second crop of crystals was collected from MeOH. Recrystallization of the combined material from MeOH afforded yellow crystals (760 g, 90%). 1: mp 82-83° C.; 1H NMR (300 Mz, CDCl3) δ 7.75 (dd, J=6.9, 1.6 Hz, 2H), 7.52-7.39 (m, 3H), 7.32-7.23 (m, 5H), 7.11 (dd, J=8.5, 2.0 Hz, 2H), 6.61 (dt, J=8.5, 2.0 Hz, 2H); 13C NMR (75 MHz, CDCl3) δ 168.7, 150.4, 139.5, 136.1, 131.6, 131.0, 129.5, 128.8, 128.3, 128.2, 122.8, 116.3, 103.6;IR(CDCl3) 3058, 3024, 1615, 1478 cm−1; Anal. Calcd for C19H14BrN: C, 67.87; H, 4.20. Found: C, 68.08; H, 4.28.

Workup

  1. additioncontaining activated molecular sieves (5 Å, 1.25 kg)
  2. customThe flask was fitted with a reflux condenser
  3. temperatureThe mixture was heated
  4. temperatureto gentle reflux
  5. temperatureheating
  6. customThe solution was decanted from the molecular sieves
  7. washthe sieves were washed with Et2O until the filtrate
  8. concentrationThe combined organic solutions were concentrated in vacuo
  9. customto give an orange oil
  10. customto crystallize at 0° C.
  11. filtrationthe precipitate was collected by filtration
  12. customa second crop of crystals was collected from MeOH
  13. customRecrystallization of the combined material from MeOH afforded yellow crystals (760 g, 90%)

Sources & evidence

ORD record
ord-36aab5d4e93147c2830332047c7c61c4
Source dataset
uspto-grants-2001_05
Patent number
US06235871B1

Reaction notes

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