tert-Butoxy bis(dimethylamino)methane → 5-Dimethylaminomethylene-4-oxo-4,5,6,7-tetrahydrobenzo[b]thiophene-2-carboxylic acid tert-butyl ester

HRID 908337Notes

Reaction equation

HRID 908337 reaction equation
[C:1]([O:5][C:6]([C:8]1[S:12][C:11]2[CH2:13][CH2:14][CH2:15][C:16](=[O:17])[C:10]=2[CH:9]=1)=[O:7])([CH3:4])([CH3:3])[CH3:2].CC(O[CH:23](N(C)C)[N:24]([CH3:26])[CH3:25])(C)C>C1(C)C=CC=CC=1>[C:1]([O:5][C:6]([C:8]1[S:12][C:11]2[CH2:13][CH2:14][C:15](=[CH:23][N:24]([CH3:26])[CH3:25])[C:16](=[O:17])[C:10]=2[CH:9]=1)=[O:7])([CH3:4])([CH3:2])[CH3:3]

Participants

4

Reactant 2

HCID 79885tert-Butoxy bis(dimethylamino)methaneHCID 592628594-Oxo-4,5,6,7-tetrahydro-benzo[b]thiophene-2-carboxylic acid tert-butyl ester

Product 1

HCID 674064945-Dimethylaminomethylene-4-oxo-4,5,6,7-tetrahydrobenzo[b]thiophene-2-carboxylic acid tert-butyl esterYield 58.3%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

4-Oxo-4,5,6,7-tetrahydro-benzo[b]thiophene-2-carboxylic acid tert-butyl ester (8.75 g, 34.68 mmol) was suspended in dry toluene (40 mL) and Bredereck's reagent (6.65 g, 38.14 mmol) was added. The resulting suspension was heated at reflux for 2 hours, during which time all starting material dissolved, allowed to cool to room temperature and concentrated under reduced pressure. The resulting oil was purified by silica gel chromatography (50% EtOAc in hexanes on 1 L silica, loaded as a solution in dichloromethane) to afford the title compound as a brown solid (6.21 g, 58% yield). MS (ES+) 308. δH (CDCl3) 1.5-1.6 (9H, s), 2.9-3.0 (2H, m), 3.0-3.1 (2H, m), 3.1 (6H, s), 7.6 (1H, s), 8.0 (1H, s).

Workup

  1. temperatureThe resulting suspension was heated
  2. temperatureat reflux for 2 hours, during which time all starting material
  3. dissolutiondissolved
  4. concentrationconcentrated under reduced pressure
  5. customThe resulting oil was purified by silica gel chromatography (50% EtOAc in hexanes on 1 L silica

Sources & evidence

ORD record
ord-62dc61355f83499c9a883d77f578aeb4
Source dataset
uspto-grants-2011_09
Patent number
US08017619B2

Reaction notes

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