N-bromobutanimide → 3-Bromo-7-chloro-6-(2-chloroethyl)-5-methylpyrazolo[1,5-a]-pyrimidine

HRID 345091Notes

Reaction equation

HRID 345091 reaction equation
[Br:1]N1C(=O)CCC1=O.[Cl:9][C:10]1[N:15]2[N:16]=[CH:17][CH:18]=[C:14]2[N:13]=[C:12]([CH3:19])[C:11]=1[CH2:20][CH2:21][Cl:22]>C(Cl)(Cl)Cl>[Br:1][C:18]1[CH:17]=[N:16][N:15]2[C:10]([Cl:9])=[C:11]([CH2:20][CH2:21][Cl:22])[C:12]([CH3:19])=[N:13][C:14]=12

Participants

4

Reactant 2

HCID 67184N-bromobutanimideHCID 156758537-Chloro-6-(2-chloroethyl)-5-methylpyrazolo[1,5-a]pyrimidine

Product 1

HCID 156758553-Bromo-7-chloro-6-(2-chloroethyl)-5-methylpyrazolo[1,5-a]-pyrimidineYield 98%

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent

Procedure

2.35 g (13.2 mmoles) of N-bromosuccinimide was added to a solution of 2.53 g (11 mmoles) of 7-chloro-6-(2-chloroethyl)-5-methylpyrazolo[1,5-a]pyrimidine (prepared as described in Example 3) dissolved in 20 ml of chloroform, and the mixture was heated under reflux, with stirring, for 30 minutes. At the end of this time, the reaction mixture was washed with a 2N aqueous solution of potassium hydroxide and then with water, after which it was dried over anhydrous sodium sulfate and then concentrated by evaporation under reduced pressure. The residue was purified by column chromatography through alumina (eluted with chloroform) and recrystallized from diisopropyl ether to afford 3.33 g (yield 98%) of the title compound as colorless needles, melting at 128.5°-129.5° C.

Workup

  1. temperaturethe mixture was heated
  2. temperatureunder reflux
  3. washAt the end of this time, the reaction mixture was washed with a 2N aqueous solution of potassium hydroxide
  4. dry with materialwith water, after which it was dried over anhydrous sodium sulfate
  5. concentrationconcentrated by evaporation under reduced pressure
  6. customThe residue was purified by column chromatography through alumina (eluted with chloroform)
  7. customrecrystallized from diisopropyl ether

Sources & evidence

ORD record
ord-c21bbd7426454ffdbf7e111fb825703a
Source dataset
uspto-grants-1991_10
Patent number
US05055479

Reaction notes

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