Potassium thiocyanate → 5-Thiocyanatopyridine-2-carboxylic acid methyl ester
Reaction equation
[CH3:1][O:2][C:3]([C:5]1[CH:10]=[CH:9][C:8](N)=[CH:7][N:6]=1)=[O:4].N([O-])=O.[Na+].[S-:16][C:17]#[N:18].[K+]>S(=O)(=O)(O)O.O>[CH3:1][O:2][C:3]([C:5]1[CH:10]=[CH:9][C:8]([S:16][C:17]#[N:18])=[CH:7][N:6]=1)=[O:4]Participants
Procedure
The starting material is prepared as follows: To the solution of 28.3 g of 5-aminopyridine-2-carboxylic acid methyl ester in 80 ml of 20% sulfuric acid, cooled to -4°, the solution of 14.31 g of sodium nitrite in 30 ml of water is added dropwise while stirring and maintaining the temperature below 0°. Thereafter the mixture is stirred for 15 minutes below 0° and the mixture of 28 g of potassium thiocyanate and 8 g of cuprous thiocyanate is added portionwise to said solution. Each addition causes evolution of gas and a black oil to separate. With continued stirring the oil again dissolves and the solution is stirred for 3 hours. It is extracted with methylene chloride, the extract filtered and evaporated, to yield the 5-thiocyanatopyridine-2-carboxylic acid methyl ester.
Workup
- customThe starting material is prepared
- temperaturemaintaining the temperature below 0°
- stirringThereafter the mixture is stirred for 15 minutes below 0°
- additionis added portionwise
- additionEach addition
- customa black oil to separate
- stirringWith continued stirring the oil
- dissolutionagain dissolves
- stirringthe solution is stirred for 3 hours
- extractionIt is extracted with methylene chloride
- filtrationthe extract filtered
- customevaporated
Sources & evidence
- ORD record
- ord-d104e4d2711341ae914c24ed7596ad2f
- Source dataset
- uspto-grants-1980_05
- Patent number
- US04202901
Reaction notes
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