Ethanolamine → 3-Bromo-1-(2'-hydroxyethyl)-5-(2'-hydroxyethyl)amino-4-nitropyrazole

HRID 1376883Notes

Reaction equation

HRID 1376883 reaction equation
[Br:1][C:2]1[C:6]([N+:7]([O-:9])=[O:8])=[C:5](Br)[N:4]([CH2:11][CH2:12][OH:13])[N:3]=1.[CH2:14]([CH2:16][NH2:17])[OH:15].O>C(O)C>[Br:1][C:2]1[C:6]([N+:7]([O-:9])=[O:8])=[C:5]([NH:17][CH2:16][CH2:14][OH:15])[N:4]([CH2:11][CH2:12][OH:13])[N:3]=1

Participants

5

Reactant 3

HCID 700EthanolamineHCID 962WaterHCID 130072363,5-Dibromo-1-(2'-hydroxyethyl)-4-nitropyrazole

Product 1

HCID 229186333-Bromo-1-(2'-hydroxyethyl)-5-(2'-hydroxyethyl)amino-4-nitropyrazoleYield 74%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

1.5 g (4.8 mmoles) of 3,5-dibromo-1-(2'-hydroxyethyl)-4-nitropyrazole are heated in a solution of 0.58 g (9.6 mmoles) ethanolamine in 30 ml ethanol for 15 hours at 80° C. After cooling, 50 ml of water are added to the reaction mixture which is then extracted three times with 70 ml of acetic acid ethyl ester. 200 ml n-hexane are added to the purified extraction solutions and the solvent mixture is vacuum distilled to a third of its original amount. Once again, n-hexane is added until the solution becomes cloudy. The crystallized product is then collected by filtration and washed with n-hexane (10 to 20 ml). 1.04 g (74 percent of theory) of 3-bromo-1-(2'-hydroxyethyl)-5-(2'-hydroxyethyl)amino-4-nitropyrazole are obtained in the form of bright yellow crystals with a melting point of 132° to 134° C.

Workup

  1. temperatureAfter cooling
  2. extractionis then extracted three times with 70 ml of acetic acid ethyl ester
  3. addition200 ml n-hexane are added to the purified extraction solutions
  4. distillationdistilled to a third of its original amount
  5. additionOnce again, n-hexane is added until the solution
  6. filtrationThe crystallized product is then collected by filtration
  7. washwashed with n-hexane (10 to 20 ml)

Sources & evidence

ORD record
ord-50d9f848224049d094c93894e6f00dab
Source dataset
uspto-grants-1997_09
Patent number
US05663366

Reaction notes

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