Thiophosgene → 5-Isothiocyanato-3-(trifluoromethyl)pyridine-2-carbonitrile

HRID 1051136Notes

Reaction equation

HRID 1051136 reaction equation
[C:1]([C:3]1[C:8]([C:9]([F:12])([F:11])[F:10])=[CH:7][C:6]([NH2:13])=[CH:5][N:4]=1)#[N:2].[C:14](Cl)(Cl)=[S:15]>O>[N:13]([C:6]1[CH:7]=[C:8]([C:9]([F:12])([F:10])[F:11])[C:3]([C:1]#[N:2])=[N:4][CH:5]=1)=[C:14]=[S:15]

Participants

4

Reactant 2

HCID 10040ThiophosgeneHCID 135322465-Amino-3-(trifluoromethyl)pyridine-2-carbonitrile

Product 1

HCID 250199805-Isothiocyanato-3-(trifluoromethyl)pyridine-2-carbonitrileYield 74%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A solution of 2-hydroxy-3-(trifluoromethyl)pyridine C in a mixture of N-iodosuccinimide (NIS), acetonitrile, and dimethylformamide (DMF) is heated at 80° C. for 2 hours to produce 2-hydroxy-3-trifluoromethyl-5-(iodo)pyridine I (greater than 80% yield). The 2-hydroxy-3-trifluoromethyl-5-(iodo)pyridine I is then mixed with POCl3 in DMF and heated to 130° C. in a microwave for 20 minutes to produce 2-chloro-3-trifluoromethyl-5-(iodo)pyridine J (yield of 50 to 55%). The 2-chloro-3-trifluoromethyl-5-(iodo)pyridine K is reacted in a solution of pMBnNH2, palladium(II) acetate, 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (BINAP), triethylamine, and cesium carbonate in toluene to produce 5-((4-methoxyphenyl))methylamino)-2-chloro-3-(trifluoromethyl)pyridine K (yield of 40%). The 5-((4-methoxyphenyl))methylamino)-2-chloro-3-(trifluoromethyl)pyridine K is reacted in a solution of zinc cyanide, tris(dibenzylideneacetone)dipalladium (Pd2(dba)3), and 1,1′-bis(diphenylphosphino)ferrocene (dppf) in DMF to provide 5-(4-methoxybenzylamine)-2-cyano-3-(trifluoromethyl)pyridine K (yield of 92%). The 5-(4-methoxybenzylamine)-2-cyano-3-(trifluoromethyl)pyridine K is reacted in a solution of dichloromethane and trifluoroacetic acid to provide 2-cyano-3-trifluoromethyl-5-(amino)pyridine H (yield greater than 95%). The 2-cyano-3-trifluoromethyl-5-(amino)pyridine H is reacted with thiophosgene in water at 25° C. for 2 hours to provide 5-isothiocyanato-3-(trifluoromethyl)pyridine-2-carbonitrile A (yield of 74% to 95%).

Sources & evidence

ORD record
ord-48d50caf473f4eaaa8ddf955e6d8f4d3
Source dataset
uspto-grants-2016_07
Patent number
US09388159B2

Reaction notes

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