Dimethylformamide → 6-Methoxy-2-(4-Methoxyphenyl)benzo[b]thiophene-3-Carboxylic Acid Chloride

HRID 850727Notes

Reaction equation

HRID 850727 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[CH:5][C:6]2[C:10]([C:11](O)=[O:12])=[C:9]([C:14]3[CH:19]=[CH:18][C:17]([O:20][CH3:21])=[CH:16][CH:15]=3)[S:8][C:7]=2[CH:22]=1.S(Cl)([Cl:25])=O.CN(C)C=O>C(Cl)Cl>[CH3:1][O:2][C:3]1[CH:4]=[CH:5][C:6]2[C:10]([C:11]([Cl:25])=[O:12])=[C:9]([C:14]3[CH:19]=[CH:18][C:17]([O:20][CH3:21])=[CH:16][CH:15]=3)[S:8][C:7]=2[CH:22]=1

Participants

5

Reactant 3

HCID 6228DimethylformamideHCID 24386Thionyl ChlorideHCID 154806536-Methoxy-2-(4-methoxyphenyl)-3-carboxybenzo[b]thiophene

Product 1

HCID 109805146-Methoxy-2-(4-Methoxyphenyl)benzo[b]thiophene-3-Carboxylic Acid ChlorideYield 97.2%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a slurry of 6-methoxy -2-(4-methoxyphenyl)benzo[b]thiophene-3-carboxylic acid (0.0484 g, 0.154 mmol) in methylene chloride (5 ml) is added thionyl chloride (0.025 ml, 0.356 mmol), and a catalytic amount of N,N-dimethylformamide. The reaction is heated to reflux for 2 hours, then cooled and concentrated in vacuo. The residual material is dissolved in toluene (10 ml), and reconcentrated in vacuo. This dissolution/reconcentration procedure is repeated two more times to afford 0.0498 g (97%) of title compound as a solid: mp 135.5-137.9° C. IR (KBr) 2965, 1678, 1610, 1525, 1478, 1253, 815; 1H NMR (CDCl3): δ8.13 (d, 1 H, J=9 Hz), 7.48 (d, 2 H, J=8.7 Hz), 7.27 (d, 1 H, J=2.4 Hz), 7.13 (dd, 1 H, J=9.0, 2.4 Hz), 7.00 (d, 2 H, J=8.7 Hz); 13C NMR (CDCl3): d 163.4, 161.0, 158.2, 139.1, 131.3, 131.2, 129.1, 128.3, 125.1, 124.6, 115.9, 114.2, 104.4, 55.7, 55.5; Exact mass calcd. for C18H16O4S (in situ-derived methyl ester): 328.0769. Found: 328.0760.

Workup

  1. temperatureThe reaction is heated
  2. temperatureto reflux for 2 hours
  3. temperaturecooled
  4. concentrationconcentrated in vacuo
  5. dissolutionThe residual material is dissolved in toluene (10 ml)
  6. dissolutionThis dissolution/reconcentration procedure

Sources & evidence

ORD record
ord-3b79a73bbbe944d496274e2d4d4e8e0f
Source dataset
uspto-grants-2000_01
Patent number
US06018056

Reaction notes

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