Thiophosgene → 2-Pyridyl isothiocyanate

HRID 1056282Notes

Reaction equation

HRID 1056282 reaction equation
[NH2:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][N:3]=1.[C:8](Cl)(Cl)=[S:9]>C1COCC1>[N:1]([C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][N:3]=1)=[C:8]=[S:9]

Participants

4

Reactant 2

HCID 10040ThiophosgeneHCID 104392-Aminopyridine

Product 1

HCID 992362-Pyridyl isothiocyanateYield 63%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
0 °C

Procedure

A solution of 2-aminopyridine (0.94 g, 9.99 mmol, Sigma Aldrich) and TEA (3.06 mL, 21.97 mmol) in THF (40.0 mL) was set stirring at 0° C. under nitrogen. A solution of thiophosgene (0.804 mL, 10.49 mmol, Fluka) in 2 mL THF was added dropwise over 5 minutes, and the reaction was stirred for 3 h at 0° C. Silica was added, and the reaction mixture was adsorbed under reduced pressure. It was purified on 16 g SiO2 (eluent: 0-100% EtOAc/hexanes over 30 min, RediSep Gold). The product fractions containing the product by TLC (50% EtOAc/hexanes) were combined and concentrated under reduced pressure to give 2-isothiocyanatopyridine (852 mg, 63%). m/z (ESI, +ve) 137.0 (M+H)+.

Workup

  1. additionSilica was added
  2. customIt was purified on 16 g SiO2 (eluent: 0-100% EtOAc/hexanes over 30 min, RediSep Gold)
  3. additionThe product fractions containing the product by TLC (50% EtOAc/hexanes)
  4. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-3c2bc4a9bc494778a3e76c6807f8bfc8
Source dataset
uspto-grants-2016_07
Patent number
US09394297B2

Reaction notes

Loading…