2-Amino-5-chloropyridine → 5-Chloro-2-isothiocyanatopyridine

HRID 861623Notes

Reaction equation

HRID 861623 reaction equation
[NH2:1][C:2]1[CH:7]=[CH:6][C:5]([Cl:8])=[CH:4][N:3]=1.[C:9](C1NC=CN=1)(C1NC=CN=1)=[S:10]>C(#N)C>[Cl:8][C:5]1[CH:6]=[CH:7][C:2]([N:1]=[C:9]=[S:10])=[N:3][CH:4]=1

Participants

4

Reactant 2

HCID 661742-Amino-5-chloropyridineHCID 11412697Thiocarbonyl diimidazole

Product 1

HCID 123832235-Chloro-2-isothiocyanatopyridineYield 36.6%

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

2-Amino-5-chloropyridine (10.28 g) was added in portions, with stirring, over a period of 25 minutes to a solution of thiocarbonyl diimidazole (14.26 g) in acetonitrile (100 ml) at ambient temperature. The stirring was continued and the solution/suspension was left at ambient temperature for a few hours. The precipitate was filtered and washed with acetonitrile (3×25 ml). The solid residue was dissolved in hot acetone and filtered. The acetone solution was evaporated in vacuo, the residue was dissolved in hot ethyl acetate and filtered through a pad of silica (diam. 7×3 cm). The silica was washed with another portion of hot ethyl acetate. The combined solutions were evaporated in vacuo to yield a crude product (5 g) of the titled product.

Workup

  1. waitthe solution/suspension was left at ambient temperature for a few hours
  2. filtrationThe precipitate was filtered
  3. washwashed with acetonitrile (3×25 ml)
  4. dissolutionThe solid residue was dissolved in hot acetone
  5. filtrationfiltered
  6. customThe acetone solution was evaporated in vacuo
  7. dissolutionthe residue was dissolved in hot ethyl acetate
  8. filtrationfiltered through a pad of silica (diam. 7×3 cm)
  9. washThe silica was washed with another portion of hot ethyl acetate
  10. customThe combined solutions were evaporated in vacuo

Sources & evidence

ORD record
ord-d68871ef5ae949069efe67b3b345a008
Source dataset
uspto-grants-1998_02
Patent number
US05714503

Reaction notes

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