Phosphorus oxide (P4O10) → 4H,5H,6H-cyclopenta(b)thiophen-6-one

HRID 2091572

Reaction equation

HRID 2091572 reaction equation
O=P12OP3(OP(OP(O3)(O1)=O)(=O)O2)=O.[S:15]1[CH:19]=[CH:18][C:17]([CH2:20][CH2:21][C:22]([OH:24])=O)=[CH:16]1>CS(O)(=O)=O>[S:15]1[CH:19]=[CH:18][C:17]2[CH2:20][CH2:21][C:22](=[O:24])[C:16]1=2

Participants

4

Reactant 2

HCID 14812Phosphorus oxide (P4O10)HCID 2689183-(Thiophen-3-yl)propanoic acid

Product 1

HCID 3156144H,5H,6H-cyclopenta(b)thiophen-6-oneYield 30.3%

Reagents, catalysts & solvents 1

HCID 6395Methanesulfonic AcidSolvent

Procedure

To a suspension of P2O5 (25.4 g, 179.0 mmol) in methanesulfonic acid (100 mL) was added 3-(thiophen-3-yl)propanoic acid (5.0 g, 32.0 mmol) and the reaction was stirred at room temperature for 1 h. At completion, the reaction was concentrated and the residue was purified by flash chromatography (20-30% EtOAc/hexane eluent) to give 4H-cyclopenta[b]thiophen-6(5H)-one (1.34 g, 30% yield) as a brown solid. 1H NMR (300 MHz, MeOH) δ ppm 8.14 (d, J=4.8 Hz, 1H), 7.17 (d, J=4.8 Hz, 1H), 2.94-3.15 (m, 4H); MS (EI) m/z=139.2 [M+1]+.

Workup

  1. concentrationAt completion, the reaction was concentrated
  2. customthe residue was purified by flash chromatography (20-30% EtOAc/hexane eluent)

Sources & evidence

ORD record
ord-0c365191e08a423e92d919537cddc9e9
Source dataset
uspto-grants-2013_05
Patent number
US08440652B2

Linked notes

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