Carbon Dioxide → HCID 19935542, compound

HRID 37437Notes

Reaction equation

HRID 37437 reaction equation
Br[C:2]1[CH:13]=[CH:12][C:5]2[C:6]([CH3:11])([CH3:10])[CH2:7][CH2:8][O:9][C:4]=2[CH:3]=1.BrCCBr.[Mg].[C:19](=[O:21])=[O:20].Cl>O1CCCC1>[CH3:10][C:6]1([CH3:11])[C:5]2[CH:12]=[CH:13][C:2]([C:19]([OH:21])=[O:20])=[CH:3][C:4]=2[O:9][CH2:8][CH2:7]1

Participants

7

Reactant 5

HCID 280Carbon DioxideHCID 313Hydrochloric AcidHCID 78391,2-DibromoethaneHCID 5462224MagnesiumHCID 223931007-Bromo-4,4-dimethylchroman

Product 1

HCID 19935542HCID 19935542, compound

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
0 °C

Procedure

A solution of 14.2 g of 7-bromo-3,4-dihydro-4,4-dimethyl-2H-1-benzopyran and 1.1 g of 1,2-dibromoethane in 80 ml of tetrahydrofuran was added dropwise using a heatable ultrasonics bath, to a suspension, boiling under reflux, of 1.6 g of magnesium shavings in 20 ml of tetrahydrofuran. After heating under reflux for an additional 2 hours, the reaction mixture was cooled to 0° C. and a strong stream of carbon dioxide gas was conducted in (about 1 hour). Thereafter, the mixture was poured on to ice, acidified with 2N hydrochloric acid and extracted with ethyl acetate. The organic extracts were washed with water, dried and evaporated. After recrystallization from ethyl acetate/hexane, there were obtained 5.3 g of 3,4-dihydro-4,4-dimethyl-2H-1-benzopyran-7-carboxylic acid, melting point 173°-174° C.

Workup

  1. temperatureAfter heating
  2. temperatureunder reflux for an additional 2 hours
  3. customwas conducted in (about 1 hour)
  4. additionThereafter, the mixture was poured on to ice
  5. extractionextracted with ethyl acetate
  6. washThe organic extracts were washed with water
  7. customdried
  8. customevaporated
  9. customAfter recrystallization from ethyl acetate/hexane

Sources & evidence

ORD record
ord-fef4d12188df48b4b48a01b0d5a3505e
Source dataset
uspto-grants-1995_05
Patent number
US05420273

Reaction notes

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