Isoamyl Nitrite → Ethyl 4-cyano-5-(methylthio)thiophene-2-carboxylate

HRID 736261Notes

Reaction equation

HRID 736261 reaction equation
N[C:2]1[C:6]([C:7]#[N:8])=[C:5]([S:9][CH3:10])[S:4][C:3]=1[C:11]([O:13][CH2:14][CH3:15])=[O:12].N(OCCC(C)C)=O>CN(C)C=O>[C:7]([C:6]1[CH:2]=[C:3]([C:11]([O:13][CH2:14][CH3:15])=[O:12])[S:4][C:5]=1[S:9][CH3:10])#[N:8]

Participants

4

Reactant 2

HCID 8053Isoamyl NitriteHCID 474798Ethyl 3-amino-4-cyano-5-(methylsulfanyl)thiophene-2-carboxylate

Product 1

HCID 816702Ethyl 4-cyano-5-(methylthio)thiophene-2-carboxylateYield 86%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent2×

Conditions

Temperature
25 °C

Procedure

A solution of 50 g (0.21 mol) of ethyl 3-amino-4-cyano-5-methylsulfanylthiophene-2-carboxylate in 500 mL of dimethylformamide under an argon atmosphere is heated to a temperature in the region of 60° C., and a solution of 71.1 mL (0.45 mol) of isopentyl nitrite in 100 mL of dimethylformamide is then introduced with stirring, while maintaining the temperature between 65 and 70° C. The reaction mixture is then stirred at a temperature in the region of 60° C. for 2.5 hours, and then cooled to a temperature in the region of 25° C. and stirred for one hour. The mixture is then treated with 1 L of ice-cold water and then stirred at a temperature in the region of 0° C. for one hour. The precipitate obtained is filtered off and then washed successively three times with 200 mL of water and three times with 200 mL of petroleum ether. 40.5 g (86%) of ethyl 4-cyano-5-methylsulfanylthiophene-2-carboxylate are thus obtained, after drying under reduced pressure, in the form of a yellow crystalline powder melting at 100° C. MS-CI (NH3): 245(+)=(M+NH4)(+).

Workup

  1. temperaturewhile maintaining the temperature between 65 and 70° C
  2. stirringThe reaction mixture is then stirred at a temperature in the region of 60° C. for 2.5 hours
  3. stirringstirred for one hour
  4. stirringstirred at a temperature in the region of 0° C. for one hour
  5. customThe precipitate obtained
  6. filtrationis filtered off
  7. washwashed successively three times with 200 mL of water and three times with 200 mL of petroleum ether

Sources & evidence

ORD record
ord-5231582215444ef79875619ad4bc354f
Source dataset
uspto-grants-2009_09
Patent number
US07595320B2

Reaction notes

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