Reaction #160360

Reaction equation

phenyl silane

1,4-cyclohexanedione monoethylene ketal

3-amino-5-phenyl-thiophene-2-carboxylic acid methyl ester

dibutyltin dichloride

→

3-(1,4-Dioxa-spiro[4.5]dec-8-ylamino)-5-phenyl-thiophene-2-carboxylic acid methyl ester

Yield 77.2%

Solvents

THF

Conditions

Workup

1. 1
   Otherresulted
2. 2
   ConcentrationIt was then concentrated
3. 3
   Otherthe residue purified by flash chromatography (0% to 30% EtOAc/Hexane)

Procedure

To a suspension of 3-amino-5-phenyl-thiophene-2-carboxylic acid methyl ester (987 mg, 4.23 mmol) in dry THF (1.0 ml), at room temperature, was added 1,4-cyclohexanedione monoethylene ketal (661 mg, 4.23 mmol), followed by dibutyltin dichloride (129 mg, 0.42 mmol). After 5 min, phenyl silane (575 μL, 4.65 mmol) was added and the reaction mixture was stirred at room temperature for 4 days when a clear solution resulted. It was then concentrated and the residue purified by flash chromatography (0% to 30% EtOAc/Hexane) to obtain 1.22 g (77%) of 3-(1,4-Dioxa-spiro[4.5]dec-8-ylamino)-5-phenyl-thiophene-2-carboxylic acid methyl ester.

Source