Diisopropylethylamine → 6-Bromo-[1,2,4]triazolo[1,5-a]pyridin-2-amine

HRID 537731Notes

Reaction equation

HRID 537731 reaction equation
Cl.NO.C([N:7](CC)C(C)C)(C)C.[Br:13][C:14]1[CH:15]=[CH:16][C:17]([NH:20][C:21]([NH:23]C(OCC)=O)=S)=[N:18][CH:19]=1>CCO.CO>[Br:13][C:14]1[CH:15]=[CH:16][C:17]2[N:18]([N:7]=[C:21]([NH2:23])[N:20]=2)[CH:19]=1

Participants

5

Reactant 3

HCID 81531DiisopropylethylamineHCID 443297Hydroxyamine hydrochlorideHCID 59286274Ethyl [(5-bromopyridin-2-yl)carbamothioyl]carbamate

Product 1

HCID 252159406-Bromo-[1,2,4]triazolo[1,5-a]pyridin-2-amineYield 69%

Reagents, catalysts & solvents 1

HCID 18681192Ethanol, mixt. with methanolSolvent

Conditions

Temperature
20 °C

Procedure

To a suspension of hydroxylamine hydrochloride (409.2 g, 5.888 mol) in EtOH/MeOH (1:1, 2.5 L) was added N,N-diisopropylethylamine (606.1 mL, 3.480 mol), the mixture was stirred at room temperature (20° C.) for 1 h. 1-(6-Bromo-pyridin-2-yl)-3-carboethoxy-thiourea (2) (352.8 g, 1.160 mol) was then added and the mixture slowly heated to reflux (Note: bleach scrubber required to quench H2S evolved). After 2 h at reflux the mixture was allowed to cool and filtered to collect the precipitated solid. The collected solid was washed successively with water (1.0 L), EtOH/MeOH (1:1, 1.0 L) and diethyl ether (500 mL) then air-dried to afford the title compound as a white solid (169.2 g, 69%). No further purification was required.

Workup

  1. temperaturethe mixture slowly heated
  2. temperatureto reflux
  3. custom(Note: bleach scrubber required to quench H2S evolved)
  4. temperatureAfter 2 h at reflux the mixture
  5. temperatureto cool
  6. filtrationfiltered
  7. customto collect the precipitated solid
  8. washThe collected solid was washed successively with water (1.0 L), EtOH/MeOH (1:1, 1.0 L) and diethyl ether (500 mL)
  9. customthen air-dried

Sources & evidence

ORD record
ord-d38b62ace34f476a970ba28b2ae2b7c7
Source dataset
uspto-grants-2014_10
Patent number
US08865699B2

Reaction notes

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