Phosgene → 2-Isocyanato-5-methyl-1,3,4-thiadiazole

HRID 838805Notes

Reaction equation

HRID 838805 reaction equation
[C:1](Cl)(Cl)=[O:2].[CH3:5][C:6]1[S:10][C:9]([NH2:11])=[N:8][N:7]=1>C(OCC)(=O)C>[CH3:5][C:6]1[S:10][C:9]([N:11]=[C:1]=[O:2])=[N:8][N:7]=1

Participants

4

Reactant 2

HCID 6371PhosgeneHCID 669491,3,4-Thiadiazole, 2-amino-5-methyl-

Product 1

HCID 542820282-Isocyanato-5-methyl-1,3,4-thiadiazole

Reagents, catalysts & solvents 1

HCID 8857Ethyl AcetateSolvent2×

Procedure

A saturated solution of phosgene in ethyl acetate (100 ml) is charged into a glass reaction vessel equipped with a mechanical stirrer. A slurry of 5-methyl-2-amino-1,3,4-thiadiazole (40 grams) in ethyl acetate (300 ml) is added to the reaction vessel and the resulting mixture is stirred for a period of about 16 hours, resulting in the formation of a precipitate. The reaction mixture is then purged with nitrogen gas to remove unreacted phosgene. The purged mixture is then filtered to recover the precipitate. The precipitate is then recrystallized to yield the desired product 5-methyl-1,3,4-thiadiazol-2-yl isocyanate dimer.

Workup

  1. customequipped with a mechanical stirrer
  2. customresulting in the formation of a precipitate
  3. customThe reaction mixture is then purged with nitrogen gas
  4. customto remove unreacted phosgene
  5. filtrationThe purged mixture is then filtered
  6. customto recover the precipitate
  7. customThe precipitate is then recrystallized

Sources & evidence

ORD record
ord-f54c2f3b2b954f6281af4a1d256b3c52
Source dataset
uspto-grants-1978_06
Patent number
US04093443

Reaction notes

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