Water → 5-tert-butyl-3-hydroxy-7-(1-methylpentadecyl)-3H-benzofuran-2one

HRID 1861572Notes

Reaction equation

HRID 1861572 reaction equation
[C:1]([C:5]1[CH:10]=[CH:9][C:8]([OH:11])=[C:7]([CH:12]([CH3:27])[CH2:13][CH2:14][CH2:15][CH2:16][CH2:17][CH2:18][CH2:19][CH2:20][CH2:21][CH2:22][CH2:23][CH2:24][CH2:25][CH3:26])[CH:6]=1)([CH3:4])([CH3:3])[CH3:2].O.[C:29](O)(=[O:32])[CH:30]=[O:31].O>ClCCCl.C1(C)C=CC(S(O)(=O)=O)=CC=1>[C:1]([C:5]1[CH:6]=[C:7]([CH:12]([CH3:27])[CH2:13][CH2:14][CH2:15][CH2:16][CH2:17][CH2:18][CH2:19][CH2:20][CH2:21][CH2:22][CH2:23][CH2:24][CH2:25][CH3:26])[C:8]2[O:11][C:30](=[O:31])[CH:29]([OH:32])[C:9]=2[CH:10]=1)([CH3:4])([CH3:3])[CH3:2]

Participants

6

Reactant 3

HCID 962WaterHCID 15620607Glyoxylic acid, monohydrateHCID 18620263HCID 18620263, compound

Product 1

HCID 186202495-tert-butyl-3-hydroxy-7-(1-methylpentadecyl)-3H-benzofuran-2oneYield 99.6%

Reagents, catalysts & solvents 2

HCID 6101p-Toluenesulfonic acidCatalystHCID 111,2-DichloroethaneSolvent

Procedure

18.7 g of 4-tert-butyl-2(1-methyl-pentadecyl)-phenol (J.Amer.Chem.Soc., 74, 1952, 3599), 5.06 g of glyoxylic acid monohydrate and 0.05 g of p-toluenesulfonic acid are heated in 40 ml of 1,2-dichloroethane for 7 hours using a water separator. The reaction solution is then cooled, washed three times with 80 ml of water each time and freed of solvent using a rotary evaporator. 21.4 g of 5-tert-butyl-3-hydroxy-7-(1-methyl-pentadecyl)-3H-benzo-furan-2-one are obtained in the form of a yellowish oil. That yellowish oil is placed in 25 ml of toluene with 8 ml of thionyl chloride and 3 drops of DMF and the reaction mixture is then slowly heated to 373 K at such a rate that the evolution of HCl and SO2 remains vigorous yet controllable. The reaction mixture is then stirred at that temperature for a further hour. Approximately 25 ml of liquid are then distilled off in order to remove the excess thionyl chloride. The residue is diluted with 80 ml of toluene and, at room temperature, 7 ml of triethylamine are added dropwise thereto. The thick, red reaction mixture is then heated under reflux for 30 min. After cooling to room temperature, the triethylamine hydrochloride which has precipitated is filtered off and the filtrate is concentrated to an oily consistency using a rotary evaporator. The isoxindigo is isolated from the residue, in the form of a waxy red mass, by chromatography on silica gel (hexane/ethyl acetate 99:1). 4.1 g (20% of the theoretical yield, based on 4-tert-butyl-2-(1-methyl-pentadecyl)-phenol) of 5,5′-di-tert-butyl-7,7′-bis(1-methyl-pentadecyl)-[3,3′]bibenzofuranylidene-2,2′-dione of formula (LIIIa) are obtained.

Workup

  1. temperatureThe reaction solution is then cooled
  2. washwashed three times with 80 ml of water each time
  3. customa rotary evaporator

Sources & evidence

ORD record
ord-0b8592baaccc430ca4a5ddbcbb609e81
Source dataset
uspto-grants-2003_03
Patent number
US06533825B2

Reaction notes

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