2-Bromo-3-pentanone → 4-Ethyl-5-methyl-1,3-thiazol-2-amine

HRID 2059047Notes

Reaction equation

HRID 2059047 reaction equation
[NH2:1][C:2]([NH2:4])=[S:3].Br[CH:6]([C:8](=O)[CH2:9][CH3:10])[CH3:7]>C(O)C>[NH2:1][C:2]1[S:3][C:6]([CH3:7])=[C:8]([CH2:9][CH3:10])[N:4]=1

Participants

4

Reactant 2

HCID 5450922-Bromo-3-pentanoneHCID 2723790Thiourea2×

Product 1

HCID 31640224-Ethyl-5-methyl-1,3-thiazol-2-amineYield 42.5%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent2×

Procedure

Thiourea (20.9 g., 0.275 mole) was dissolved in 250 ml. of refluxing ethanol. 2-Bromo-3-pentanone (41.3 g., 0.25 mole), dissolved in 50 ml. of ethanol, was added dropwise over 25 minutes to the refluxing thiourea solution. Following an additional 2 hours of reflux, the reaction was boiled down to approximately 100 ml., cooled and the crude product recovered as the hydrobromide salt by filtration. Purified 2-amino-4-ethyl-5-methylthiazole (15.1 g.; m.p. 45°-50° C.; m/e calcd: 142; found: 142) was obtained by dissolution in water and reprecipitation with aqueous 3 N potassium hydroxide.

Workup

  1. temperatureof reflux
  2. temperature, cooled
  3. filtrationthe crude product recovered as the hydrobromide salt by filtration

Sources & evidence

ORD record
ord-6c29bfc06bf545178ce0bd59dcc0dc2a
Source dataset
uspto-grants-1982_03
Patent number
US04321372

Reaction notes

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