Sulfuric Acid → HCID 68731984, compound

HRID 341663Notes

Reaction equation

HRID 341663 reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][C:5]([CH:8]2[C:10]3([C:19]([CH3:21])([CH3:20])[O:18][C:12]4([CH2:17][CH2:16][CH2:15][CH2:14][CH2:13]4)[C:11]3=[O:22])[O:9]2)=[C:4]([CH2:23][CH3:24])[CH:3]=1.BrC1C=CC(C2C3(C(=O)C(C)(C)OC43CCCCC4)O2)=C(CC)C=1.S(=O)(=O)(O)O>ClCCl>[Br:1][C:2]1[CH:7]=[CH:6][C:5]([CH:8]2[C:11](=[O:22])[C:12]3([CH2:17][CH2:16][CH2:15][CH2:14][CH2:13]3)[O:18][C:19]([CH3:21])([CH3:20])[C:10]2=[O:9])=[C:4]([CH2:23][CH3:24])[CH:3]=1

Participants

5

Reactant 3

HCID 1118Sulfuric AcidHCID 59562691HCID 59562691, compoundHCID 59562702HCID 59562702, compound

Product 1

HCID 68731984HCID 68731984, compound

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Conditions

Temperature
7.5 °C

Procedure

To an ice cold solution of mixture of 2-(4-bromo-2-ethylphenyl)-12,12-dimethyl-1,11-dioxadispiro[2.1.5.2]dodecan-4-one and 2-(4-bromo-2-ethylphenyl)-11,11-dimethyl-1,10-dioxadispiro[2.0.5.3]dodecan-12-one (15 g, 0.038 mol) in dichloromethane (7.5 ml) is added concentrated sulphuric acid (45 ml), dropwise, over 50-60 minutes, maintaining the temperature of the reaction mixture at 5-10° C. The reaction mixture is maintained at 5-10° C. for 10-15 minutes, quenched into crushed ice (225 g) and extracted with dichloromethane (3×100 ml). The organic phases are combined, washed with water and dried over anhydrous sodium sulfate. The mixture is filtered and the filtrate is evaporated under reduced pressure. The residue is purified by column chromatography on silica gel to give 4-(4-bromo-2-ethylphenyl)-2,2-dimethyl-1-oxaspiro[5.5]undecane-3,5-dione (3 g) as a white solid.

Workup

  1. temperatureThe reaction mixture is maintained at 5-10° C. for 10-15 minutes
  2. customquenched
  3. custominto crushed ice (225 g)
  4. extractionextracted with dichloromethane (3×100 ml)
  5. washwashed with water
  6. dry with materialdried over anhydrous sodium sulfate
  7. filtrationThe mixture is filtered
  8. customthe filtrate is evaporated under reduced pressure
  9. customThe residue is purified by column chromatography on silica gel

Sources & evidence

ORD record
ord-a43d770d986147cfade059d12059b588
Source dataset
uspto-grants-2014_11
Patent number
US08895761B2

Reaction notes

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