HCID 178508074, compound → HCID 178507367, compound

A suspension of 4-amino-5-nitrobenzotriazole (0.72 g, 4 mmol) in 100 ml of ethanol and 1 ml of conc. hydrochloric acid was hydrogenated at atmospheric pressure and room temperature for 6 h in the presence of 100 mg of 5% palladium-on-charcoal. The mixture was filtered and the catalyst was washed with about 50 ml of water. The combined filtrate was evaporated to dryness giving 0.70 g of the 4,5-diamino-benzotriazole as an hydrochloride. A solution of the crude diamino compound in 40 ml of 4M hydrochloric acid was refluxed with oxalic acid dihydrate (0.50 g, 4 mmol) for 3 h. The mixture was cooled on ice, and pH was adjusted to 5-6 with 2N sodium hydroxide. The precipitate was filtered off and washed with water and ethanol. It was then dissolved in 10 ml of 2N sodium hydroxide, treated with decolourising charcoal, and filtered. After adjustment to pH 6-7 with 4M hydrochloric acid the reprecipitated product was isolated, washed with water and ethanol, and dried at 100 ° C. affording 0.12 g (15%) of pure title compound; m.p.>300° C.; IR (KBr): 3200-2000, 1670 cm-1 ; 1H-NMR (DMSO-d6): 6.9 (broad s, 3H, NH+2OH); 7.03 (d,J=8 Hz, 1H, ArH); 7.43 (d,J=8 Hz,1H, ArH).

1. filtrationThe mixture was filtered
2. washthe catalyst was washed with about 50 ml of water
3. customThe combined filtrate was evaporated to dryness

ORD record

ord-d23751579b164a06ae94a5cbd66c0fee

Source dataset

uspto-grants-1991_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05075306