Reaction #1702083

Reaction equation

methyl 3-amino-5-(3,3-dimethylbut-1-ynyl)thiophene-2-carboxylate

1-Methoxy-1-oxo-1λ5 phosphinan-4-one

dibutyltin dichloride

phenylsilane

→

title compound

Yield 85.0%

Methyl 5-(3,3-Dimethyl-but-1-ynyl)-3-(1-methoxy-1-oxo-1 λ5phosphinan-4-ylamino)-thiophene-2-carboxylate

Yield 85.0%

Solvents

THF

DMF

Conditions

Workup

1. 1
   Otherpartitioned between water and ethyl acetate
2. 2
   ExtractionThe aqueous phase was extracted with ethyl acetate
3. 3
   WashThe combined organic layers were washed with 5% LiCl and brine
4. 4
   Dryingdried over magnesium sulfate
5. 5
   Filtrationfiltered
6. 6
   Concentrationconcentrated
7. 7
   OtherThe residue was purified by silica gel column chromatography

Procedure

A solution of methyl 3-amino-5-(3,3-dimethylbut-1-ynyl)thiophene-2-carboxylate (474 mg, 2 mmol) and 1-Methoxy-1-oxo-1λ5 phosphinan-4-one (390 mg, 2.4 mmol) in THF (1 mL) and DMF (1 mL) was treated with dibutyltin dichloride (60 mg, 0.2 mmol). After 5 min, phenylsilane (272 μL, 2.2 mmol) was added, and the mixture was stirred for one hour at room temperature and then partitioned between water and ethyl acetate. The aqueous phase was extracted with ethyl acetate. The combined organic layers were washed with 5% LiCl and brine, dried over magnesium sulfate, filtered and concentrated. The residue was purified by silica gel column chromatography using EtOAc:Hexanes as eluent to provide 650 mg (85%) of title compound: MS (m/z) 384.0 [M+H]+; HPLC retention time: 4.463 min (2-98% acetonitrile:water with 0.05% trifluoroacetic acid).

Source