Phosphorus oxide (P4O10) → 3,4-Dihydro-[1]benzothieno[3,2-c]pyridin-1(2H)-one

HRID 703781Notes

Reaction equation

HRID 703781 reaction equation
[S:1]1[C:5]([CH2:6][CH2:7][NH:8][C:9](=O)[O:10]CC)=[CH:4][C:3]2[CH:14]=[CH:15][CH:16]=[CH:17][C:2]1=2.O=P12OP3(OP(OP(O3)(O1)=O)(=O)O2)=O>O>[C:9]1(=[O:10])[C:4]2[C:3]3[CH:14]=[CH:15][CH:16]=[CH:17][C:2]=3[S:1][C:5]=2[CH2:6][CH2:7][NH:8]1

Participants

4

Reactant 2

HCID 14812Phosphorus oxide (P4O10)HCID 53768472Ethyl [2-(benzo[b]thiophen-2-yl)ethyl]carbamate

Product 1

HCID 200749053,4-Dihydro-[1]benzothieno[3,2-c]pyridin-1(2H)-oneYield 15.1%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A mixture of ethyl [2-(benzo[b]thiophen-2-yl)ethyl]carbamate (285 mg), polyphosphoric acid (4 g) and phosphorus pentoxide (250 mg) was heated at 100°-110° for 6h. The cooled mixture was treated with water (25 ml) and the suspension was extracted with ethyl acetate (3×25 ml) The combined, dried organic extracts were purified by SPCC eluting with System B (1:1) to give the title compound (35 mg) as a solid, m.p. 143°-144°.

Workup

  1. temperaturewas heated at 100°-110° for 6h
  2. extractionthe suspension was extracted with ethyl acetate (3×25 ml) The
  3. customdried organic extracts were purified by SPCC
  4. washeluting with System B (1:1)

Sources & evidence

ORD record
ord-7d77efc459a144eaba9edb0aec825b1f
Source dataset
uspto-grants-1991_01
Patent number
US04985422

Reaction notes

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