Benzoic Acid → Diphenylamine

HRID 1792994Notes

Reaction equation

C(O)(=O)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[NH2:10][C:11]1[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1.C[Si](C)(C)N[Si](C)(C)C.[Li].C([N-]C(C)C)(C)C.[Li+]>CN(C)C=O.C(#N)C.O1CCCC1>[C:11]1([NH:10][C:2]2[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=2)[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1

Participants

Conditions

Temperature: -78 °C

Procedure

In Scheme 1, Step A, a 2-(arylamino)-benzoic acid or diphenylamine (3) is prepared from the coupling of a suitable benzoic acid (1) and a suitable aniline (2) in the presence of a strong base, for example, lithium 1,1,1,3,3,3-hexamethyldisilazane (LiHMDS) or lithium diisopropylamide, in a polar aprotic solvent such as tetrahydrofuran, acetonitrile or dimethylformamide. For example, the aniline (2) and the benzoic acid (1) are dissolved in a suitable organic solvent and cooled to about −78° C. under nitrogen. The suspension is treated with an excess of a suitable base, such as LiHMDS, and allowed to warm to room temperature. The reaction is typically complete within about 2 hours to about 5 days. The resulting benzoic acid (3) can be isolated by removing the solvent, for example by evaporation under reduced pressure or by filtering the precipitated solid through Celite® and washing with a suitable solvent. The benzoic acid (3) can be further purified, if desired, by standard methods such as chromatography, crystallization, or distillation.

Workup

additionThe suspension is treated with an excess of a suitable base
temperatureto warm to room temperature
waitThe reaction is typically complete within about 2 hours to about 5 days

Sources & evidence

ORD record: ord-cf997285b9ea42099c032ff04f577df5
Source dataset: uspto-grants-2006_07
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07078438B2

Reaction notes

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