Ethylenediamine → Brimonidine

HRID 880349Notes

Reaction equation

HRID 880349 reaction equation
[Br:1][C:2]1[C:11]([N:12]=[C:13]=S)=[CH:10][CH:9]=[C:8]2[C:3]=1[N:4]=[CH:5][CH:6]=[N:7]2.[CH2:15]([NH2:18])[CH2:16][NH2:17]>C1C=CC=CC=1>[Br:1][C:2]1[C:11]([NH:12][C:13]2[NH:17][CH2:16][CH2:15][N:18]=2)=[CH:10][CH:9]=[C:8]2[C:3]=1[N:4]=[CH:5][CH:6]=[N:7]2

Participants

4

Reactant 2

HCID 3301EthylenediamineHCID 44602745-Bromo-6-isothiocyanatoquinoxaline2×

Product 1

HCID 2435Brimonidine

Reagents, catalysts & solvents 1

HCID 241BenzeneSolvent2×

Procedure

The 5-bromo-6-isothiocyanato-quinoxaline (3.5 g.) is directly dissolved in benzene (400 ml) and added dropwise to a well-stirred solution of ethylene diamine (15 g.) in benzene (50 ml). During a period of about two hours, an oil separates as a lower layer. The upper benzene layer is poured off and the oil is washed with diethyl ether and then dissolved in methanol (500 ml). The methanolic solution is refluxed until hydrogen sulfide evolution ceases. The methanolic solution is concentrated in vacuo to a volume of approximately 100 ml upon which a yellow solid precipitates. The precipitate is collected by filtration and recrystallized from methanol to afford of (5-Bromo-quinoxalin-6-yl)-(4,5-dihydro-1H-imidazol-2-yl)-amine: m.p. 250-251 C.

Workup

  1. washthe oil is washed with diethyl ether
  2. dissolutiondissolved in methanol (500 ml)
  3. temperatureThe methanolic solution is refluxed until hydrogen sulfide evolution ceases
  4. concentrationThe methanolic solution is concentrated in vacuo to a volume of approximately 100 ml upon which a yellow solid
  5. customprecipitates
  6. filtrationThe precipitate is collected by filtration
  7. customrecrystallized from methanol

Sources & evidence

ORD record
ord-b3bea7d9a6b04d1eb504156ae990065f
Source dataset
uspto-grants-2015_03
Patent number
US08993571B2

Reaction notes

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