Hydrochloric Acid → 1-methyl-1H-1,2,3-benzotriazole-5-carboxylic acid

HRID 252859Notes

Reaction equation

[NH2:1][C:2]1[CH:3]=[C:4]([CH:8]=[CH:9][C:10]=1[NH:11][CH3:12])[C:5]([OH:7])=[O:6].Cl.[N:14]([O-])=O.[Na+].[OH-].[K+]>O>[CH3:12][N:11]1[C:10]2[CH:9]=[CH:8][C:4]([C:5]([OH:7])=[O:6])=[CH:3][C:2]=2[N:1]=[N:14]1

Participants

Conditions

Temperature: 0 °C

Procedure

To a stirred suspension of the diamine 280 (1.08 g; 6.48 mmol) (or any other o-arylenediamine) in water (25 mL) at 0° C., concentrated HCl (5.4 mL) was added drop wise followed by slow addition of a solution of NaNO2 (643 mg; 9.3 mmol) in water (10 mL). The reaction mixture was stirred at 0° C. for 2 h and then was allowed to warm up to 10° C. over 4 h; neutralized with a solution of KOH (5.6 g) in water (30 mL) (final pH=6); concentrated and purified by preparative HPLC in reverse phase mode (column aquasil C-18, elution 5% to 95% MeOH in water), to afford the title compound 284 (211 mg; 18% yield). 1H NMR: (400.2 MHz, DMSO) δ (ppm): 8.35 (s; 1H); 8.08 (dd, J=1.4, 8.6 Hz; 1H); 7.75 (d, J=1.4 Hz; 1H); 4.03 (s, 3H). MS: calc: 177.1; found: 178.1 (M+H).

Workup

temperatureto warm up to 10° C. over 4 h
concentrationconcentrated
custompurified by preparative HPLC in reverse phase mode (column aquasil C-18, elution 5% to 95% MeOH in water)

Sources & evidence

ORD record: ord-37b78c481ad04acb870aa797bd5fddd8
Source dataset: uspto-grants-2011_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07868205B2

Reaction notes

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