2,3-Dihydro-6-methoxy-2-(4-methoxyphenyl)benzo[b]thiophene-3-carboxylic acid methyl ester → 6-Methoxy-2-(4-Methoxyphenyl)benzo[b]thiophene-3-Carboxylic Acid Methyl Ester

HRID 850724Notes

Reaction equation

HRID 850724 reaction equation
[CH3:1][O:2][C:3]([CH:5]1[CH:9]([C:10]2[CH:15]=[CH:14][C:13]([O:16][CH3:17])=[CH:12][CH:11]=2)[S:8][C:7]2[CH:18]=[C:19]([O:22][CH3:23])[CH:20]=[CH:21][C:6]1=2)=[O:4]>C1(C)C=CC=CC=1>[CH3:1][O:2][C:3]([C:5]1[C:6]2[CH:21]=[CH:20][C:19]([O:22][CH3:23])=[CH:18][C:7]=2[S:8][C:9]=1[C:10]1[CH:11]=[CH:12][C:13]([O:16][CH3:17])=[CH:14][CH:15]=1)=[O:4]

Participants

3

Reactant 1

HCID 154582622,3-Dihydro-6-methoxy-2-(4-methoxyphenyl)benzo[b]thiophene-3-carboxylic acid methyl ester

Product 1

HCID 543901236-Methoxy-2-(4-Methoxyphenyl)benzo[b]thiophene-3-Carboxylic Acid Methyl EsterYield 98%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

To toluene (20 ml) and 2,3-dihydro-6-methoxy-2-(4-methoxyphenyl)benzo[b]thiophene-3-carboxylic acid methyl ester (0.7365 g, 2.33 mmol) is added dichlorodicyanoquinone (0.5405 g, 2.38 mmol, 2.38 mmol). The mixture is placed under nitrogen and heated to reflux for 16 hours, then cooled and filtered. The filter cake is rinsed with additional toluene and the filtrate and rinse are combined and concentrated to afford crude product, which is purified by silica gel chromatography (9:1 hexanes:ethyl acetate) to afford 0.7178 g (98%) of title compound: mp 85.4-86.6° C.; IR (KBr) 3010, 2860, 1700, 1608, 1478, 1251, 1068, 1020 cm-1 ; 1H NMR (CDCl3): δ8.21 (d, 1 H, J=8.7 Hz), 7.44 (d, 2 H, J=8.4 Hz), 7.24 (s, 1 H), 7.07 (d, 1 H, J=9 Hz), 6.95 (d, 2 H, J=8.4 Hz), 3.87 (s, 3 H), 3.85 (s, 3 H), 3.78 (s, 3 H); 13C NMR (CDCl3): d 164.6, 160.2, 157.7, 149.6, 139.8, 132.7, 130.9, 126.4, 125.4, 115.2, 113.7, 104.2, 55.7, 55.4, 51.6. Anal. Calcd. for C18H16O4S: C, 65.84; H, 4.91; S, 9.76. Found: C, 65.72; H, 4.90; S, 10.04.

Workup

  1. temperatureheated
  2. temperatureto reflux for 16 hours
  3. temperaturecooled
  4. filtrationfiltered
  5. washThe filter cake is rinsed with additional toluene
  6. washthe filtrate and rinse
  7. concentrationconcentrated
  8. customto afford crude product, which
  9. customis purified by silica gel chromatography (9:1 hexanes:ethyl acetate)

Sources & evidence

ORD record
ord-07f5000716f144ffb1ca74cc33400917
Source dataset
uspto-grants-2000_01
Patent number
US06018056

Reaction notes

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