4-Aminobenzoic Acid → Benzimidazole

HRID 33756

Reaction equation

HRID 33756 reaction equation
[NH2:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[NH2:8][C:9]1[CH:17]=[CH:16][C:12]([C:13]([OH:15])=O)=[CH:11][CH:10]=1.[N-:18]=[C:19]=[S:20].C(Cl)(Cl)=S.[C:25]([CH2:27][C:28]([NH2:30])=[O:29])#[N:26]>>[NH2:8][C:9]1[CH:10]=[CH:11][C:12]([C:13]2[O:15][C:3]3[CH:4]=[CH:5][CH:6]=[CH:7][C:2]=3[N:1]=2)=[CH:16][CH:17]=1.[S:20]1[C:3]2[CH:4]=[CH:5][CH:6]=[CH:7][C:2]=2[N:18]=[CH:19]1.[N:1]1[C:2]2[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=2[NH:26][CH:25]=1.[C:19]([CH:27]([C:25]#[N:26])[C:28]([NH2:30])=[O:29])(=[S:20])[NH2:18]

Participants

9

Procedure

The 2-(4-aminophenyl)benzoxazole, benzothiazole, or benzimidazole was prepared by condensation of the appropriate aniline derivative with p-amino benzoic acid using polyphosphoric acid. The product was converted to the corresponding isothiocyanate with thiophosgene and subsequently condensed with cyanoacetamide to form the thiocarbamoyl cyanoacetamide. Treatment with bromine afforded the cyano hydroxy thiazole, which was converted to carboxamidine by treatment with the appropriate amide, as shown above.

Sources & evidence

ORD record
ord-ffad715435b24c70909bdbc409e32c04
Source dataset
uspto-grants-2008_09
Patent number
US07429667B2

Linked notes

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