Hydrochloric Acid → 5-Ethoxy-7-fluoro-1,2,4-triazolo[4,3-c]pyrimidine-3(2H)-thione

HRID 374584Notes

Reaction equation

HRID 374584 reaction equation
[CH2:1]([O:3][C:4]1[N:9]=[C:8]([F:10])[CH:7]=[C:6]([NH:11][NH2:12])[N:5]=1)[CH3:2].[C:13](=S)=[S:14].[O-]CC.[Na+].Cl>C(O)C.O>[CH2:1]([O:3][C:4]1[N:5]2[C:13](=[S:14])[NH:12][N:11]=[C:6]2[CH:7]=[C:8]([F:10])[N:9]=1)[CH3:2]

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 6348Carbon DisulfideHCID 2723922Sodium ethoxideHCID 109429042-Ethoxy-4-fluoro-6-hydrazinylpyrimidine

Product 1

HCID 118060545-Ethoxy-7-fluoro-1,2,4-triazolo[4,3-c]pyrimidine-3(2H)-thioneYield 40%

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 962WaterSolvent

Procedure

A 1.74 g (10 mmol) sample of 2-ethoxy-4-fluoro-6-hydrazinopyrimidine was dissolved in 20 mL of absolute ethanol and 2.84 g (37 mmol) of carbon disulfide and 3.20 g (10 mmol) of 21 percent by weight sodium ethoxide were added. The mixture was heated at reflux with stirring for 3 hours and then was cooled by adding 20 mL of ice water. The mixture was then acidified to a pH of about 2 by adding 2 mL of 6.25N hydrochloric acid diluted to 8 mL with water. The yellow precipitate that formed was recovered by filtration, washed with water, and dried to obtain 0.85 g (40 percent of theory) of 5-ethoxy-7-fluoro-1,2,4-triazolo[4,3-c]pyrimidine-3(2H)-thione. The proton and carbon NMR spectra of this material were consistent with its assigned structure.

Workup

  1. temperatureThe mixture was heated
  2. temperatureat reflux
  3. temperaturewas cooled
  4. customThe yellow precipitate that formed
  5. filtrationwas recovered by filtration
  6. washwashed with water
  7. customdried

Sources & evidence

ORD record
ord-815dd1e2a8c040e4b5bf26240d4b1f18
Source dataset
uspto-grants-1996_01
Patent number
US05480991

Reaction notes

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