Chemical Properties
Clear colorless to yellow liquid
Uses
4,4-Dimethoxy-2-butanone (β-ketobutyracetal) may be used in the preparation of:
- (R)-4,4-dimethoxy-2-butanol
- pyrazoles and pyrimidines
- [7,16-dihydro- 6,15( 17)-dimetbyldibenzo[b,i]-[1,4,8,11]tetrilazacyclotetradecinato-N5,N9,N14,N18]nickel{II)
Uses
Acetaldehyde dimethyl acetal is used as a flavoring agent. It is also used in the preparation of (R)-4,4-dimethoxy-2-butanol, pyrazoles and pyrimidines. Further, it is used in the preparation of N,N-diethyl-[2-(4-fluorophenyl)-5-methylpyrazolo[1,5-a]-pyrimidin-3-yl]acetamide and acetoacetaldehyde.
Definition
ChEBI: 4,4-Dimethoxy-2-butanone is a ketone.
General Description
4,4-Dimethoxy-2-butanone (Acetylacetaldehyde dimethylacetal) is a ketone.
Synthesis
Methanol was added to the 3L and 2L flasks, 257 g of sodium methanolate (1.852 mol) was dissolved in methanol and the temperature was maintained at 40 °C. A mixture of 118.1 g of acetone (2.036 mol) and 333.6 g of methyl formate (5.555 mol) was added dropwise to the reaction system at 40 °C for 4 hours. After the dropwise addition, stirring was continued for 1 h. Subsequent cooling to 20 °C gave 184 g of formalin acetone sodium salt (92% quantitative yield by HPLC using sodium methanol as standard). The resulting formalin acetone sodium salt was transferred to a necked down 3L reactor, methanol was added, and 6.2 g of sulfuric acid (0.063 mol) was added, keeping the temperature at 30 °C. The reaction solution of formylacetone was added to the reaction system simultaneously with 93.8 g of sulfuric acid (0.957 mol) dropwise at 30 °C or lower for 1 hour, during which the pH was maintained between 0-1. After completion of the dropwise addition, the mixture was continued to be stirred at the same temperature for 4 hours and subsequently cooled to 20°C. The pH was adjusted to 7-8 with 20% sodium hydroxide solution, the resulting salt was removed by filtration, and the distillate was collected by distillation to give a final 195.6 g of 4,4-dimethoxy-2-butanone (80.0% yield based on sodium methanol and 87.0% yield based on formalin acetone sodium salt).
Toxics Screening Level
The ITSL for 4,4-dimethoxy-2-butanone is 20 μg/m3 annual average.
References
[1] Patent: KR2017/17372, 2017, A. Location in patent: Paragraph 0047; 0065-0070