DIMETHYL PROPARGYLMALONATE

DIMETHYL PROPARGYLMALONATE Property

Boiling point:

93-95 °C/7 mmHg (lit.)

Density 

1.119 g/mL at 20 °C (lit.)

refractive index 

n20/D 1.444

Flash point:

113 °C

storage temp. 

Sealed in dry,Room Temperature

pka

11.75±0.59(Predicted)

form 

liquid

Appearance

Colorless to light yellow Liquid

BRN 

3539408

Safety

Safety Statements 

23-24/25

WGK Germany 

3

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H315Causes skin irritation

H319Causes serious eye irritation

H335May cause respiratory irritation

Precautionary statements

P264Wash hands thoroughly after handling.

P264Wash skin thouroughly after handling.

P280Wear protective gloves/protective clothing/eye protection/face protection.

P302+P352IF ON SKIN: wash with plenty of soap and water.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

P321Specific treatment (see … on this label).

P332+P313IF SKIN irritation occurs: Get medical advice/attention.

P362Take off contaminated clothing and wash before reuse.

DIMETHYL PROPARGYLMALONATE Chemical Properties,Usage,Production

Uses

Dimethyl propargylmalonate can be used as a reactant to synthesize:

• Nitro methylenecyclopentanes by [3+2] annulation reaction with various nitroalkenes in the presence of Triton B.
• Propargylmalonamides intermediates, applicable in the preparation of ″click BOX″ ligands by copper-catalyzed cycloaddition and oxazoline ring formation reaction.
• Cyclopentene derivatives by reacting with various α, β-unsaturated ketones using a combination of organocatalysts and transition metal catalysts.

Synthesis

1. A sodium ethanolate solution was prepared by slowly adding sodium metal flakes (2.30 g, 100 mmol) to anhydrous ethanol (100 mL) at room temperature. 2. After the above sodium ethanol solution was cooled to 0°C, dimethyl malonate (16.0 g, 100 mmol) was added dropwise under stirring within 10 minutes. 3. After the dropwise addition, the reaction was kept at 0 °C for 15 min, after which the reaction mixture was slowly warmed up to room temperature and stirring was continued for 50 min. 4. The resulting enolide solution was cooled to 0 °C again and 3-bromopropyne (11.9 g, 100 mmol) was slowly added over 20 min. 5. After completion of the addition, the reaction was kept at 0 °C for 30 min, after which the reaction mixture was slowly warmed to room temperature with stirring overnight. 6. After completion of the reaction, the solvent was removed by evaporation under reduced pressure and the residue was washed with distilled water. 7. The aqueous layer was extracted twice with ether (Et2O) and the organic layers were combined. 8. The organic layer was dried with anhydrous sodium sulfate (Na2SO4), filtered and evaporated under reduced pressure to remove the solvent. 9. 9. The residue was purified by distillation and silica gel column chromatography (eluent: petroleum ether-ethyl acetate, 10:1) to afford dimethyl acetylmalonate (11.9 g, 60.0 mmol) in 60% yield. Note: This product can also be prepared by reacting triethyl dodecyl formate oxide with 3-bromopropyne.

References

[1] Angewandte Chemie - International Edition, 2014, vol. 53, # 30, p. 7913 - 7917
[2] Angew. Chem., 2014, vol. 126, # 30, p. 8047 - 8051,5
[3] Advanced Synthesis and Catalysis, 2016, vol. 358, # 12, p. 2007 - 2011
[4] Chemical Communications, 2014, vol. 50, # 5, p. 593 - 595
[5] Organic Letters, 2013, vol. 15, # 3, p. 582 - 585