4,5-dihydro-1H-imidazole-2-sulfonic acid → Brimonidine

HRID 654282Notes

Reaction equation

HRID 654282 reaction equation
[NH2:1][C:2]1[C:3]([Br:12])=[C:4]2[C:9](=[CH:10][CH:11]=1)[N:8]=[CH:7][CH:6]=[N:5]2.[NH:13]1[CH2:17][CH2:16][N:15]=[C:14]1S(O)(=O)=O>C(O)C(C)C>[Br:12][C:3]1[C:2]([NH:1][C:14]2[NH:15][CH2:16][CH2:17][N:13]=2)=[CH:11][CH:10]=[C:9]2[C:4]=1[N:5]=[CH:6][CH:7]=[N:8]2

Participants

4

Reactant 2

HCID 2745614,5-dihydro-1H-imidazole-2-sulfonic acidHCID 149284425-Bromoquinoxalin-6-amine

Product 1

HCID 2435BrimonidineYield 61%

Reagents, catalysts & solvents 1

HCID 6560IsobutanolSolvent

Procedure

A mixture of 6-amino-5-bromo quinoxaline (prepared using the method reported by Danielewicz U.S. Pat. No. 3,890,319) (0.224 g, 2 mmol), imidazoline-2-sulfonic acid (0.30 g, 2 mmol) and isobutanol (3 ml) was heated to 125° C. and maintained at this temperature for 16 hours. The mixture was then cooled to room temperature and concentrated in vacuo to give a brown residue which was chromatographed (silica gel, 9:1 CHCl3 /CH3OH saturated with NH3 (g)) to yield 0.177 g (a yield of 61%) of the title compound as a yellow solid, which was characterized spectroscopically.

Workup

  1. customprepared
  2. temperaturemaintained at this temperature for 16 hours
  3. concentrationconcentrated in vacuo
  4. customto give a brown residue which
  5. customwas chromatographed (silica gel, 9:1 CHCl3 /CH3OH saturated with NH3 (g))

Sources & evidence

ORD record
ord-7f02335c95f9472692aa7fa5bc54ecb4
Source dataset
uspto-grants-1992_07
Patent number
US05130441

Reaction notes

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