Ethane → (3,3-Dimethoxyprop-1-yn-1-yl)cyclopropane

HRID 1367636Notes

Reaction equation

HRID 1367636 reaction equation
[Mg].C(Br)C.[CH:5]1([C:8]#[CH:9])[CH2:7][CH2:6]1.CC.[CH3:12][O:13][CH:14](OC)[O:15][CH3:16]>O1CCCC1.C1(C)C=CC=CC=1>[CH3:12][O:13][CH:14]([O:15][CH3:16])[C:9]#[C:8][CH:5]1[CH2:7][CH2:6]1

Participants

8

Reactant 5

HCID 6324EthaneHCID 6332Ethyl BromideHCID 9005Trimethyl orthoformateHCID 138823CyclopropylacetyleneHCID 5462224Magnesium

Product 1

HCID 29921341(3,3-Dimethoxyprop-1-yn-1-yl)cyclopropane

Reagents, catalysts & solvents 2

HCID 1140TolueneSolventHCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
55 °C

Procedure

Magnesium (26.7 g, 1.1 mol) was suspended in 350 ml tetrahydrofurane and ethylbromide (74.6 ml, 1 mol) was added at such a rate, that the tetrahydrofurane continued to reflux. After completion of the addition the mixture was stirred one hour at 50-60° C. to complete the reaction. After cooling to room temperature ethynyl-cyclopropane 7 (80.6 ml, 70% in toluene, 0.95 mol) was added slowly during 30 minutes (evolution of ethane!) to the Grignard-reagent. After the addition the mixture was stirred one more hour at RT before trimethylorthoformate (120.3 ml, 1.1 mol) and toluene (400 ml) were added. The mixture was heated up (oil-bath temperature 100°-120° C.) and the tetrahydrofurane was removed by distillation during 4 hours. After cooling to RT and stirring over night the reaction mixture was diluted by addition of TBME (500 ml) and water was slowly added (50 ml). The clear organic solution was decanted from the highly viscous magnesium hydroxide phase. The magnesium hydroxide phase was extracted two more times with TBME (2 times 100 ml) and the combined organic solutions were dried over magnesium sulfate, filtered and concentrated. Compound 8 was isolated through vacuum-distillation (10 mbar, bp: 55°-60° C., 99 g, 0.7 mol).

Workup

  1. temperatureto reflux
  2. additionAfter completion of the addition the mixture
  3. customthe reaction
  4. additionAfter the addition the mixture
  5. additionwere added
  6. temperatureThe mixture was heated up (oil-bath temperature 100°-120° C.)
  7. customthe tetrahydrofurane was removed by distillation during 4 hours
  8. temperatureAfter cooling to RT
  9. stirringstirring over night the reaction mixture
  10. additionwas diluted by addition of TBME (500 ml) and water
  11. additionwas slowly added (50 ml)
  12. customThe clear organic solution was decanted from the highly viscous magnesium hydroxide phase
  13. extractionThe magnesium hydroxide phase was extracted two more times with TBME (2 times 100 ml)
  14. dry with materialthe combined organic solutions were dried over magnesium sulfate
  15. filtrationfiltered
  16. concentrationconcentrated

Sources & evidence

ORD record
ord-c38ad9c585bd40a18bce9506516c637a
Source dataset
uspto-grants-2011_02
Patent number
US07893262B2

Reaction notes

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