Ethylene Glycol → 2-Methyl-1,3-Dioxolane-2-Carboxylic Acid

温度

40 °C

To a stirred mixture containing ethyl pyruvate (11.1 mL, 0.1 mol) and ethylene glycol (5.6 mL, 0.1 mol) in anhydrous dichloromethane (100 mL) at 0° C. was added boron trifluoride dietherate (6.4 mL, 0.05 mol) and catalytic amount of acetic acid. The resulting mixture was stirred at 40° C. for 16 h and then diluted with 100 mL of dichloromethane. The organic solution was washed successively with saturated sodium chloride solution (2×80 mL). The organic layer was separated and the combined organic extracts were concentrated. The residue was treated with 1N sodium hydroxide at room temperature. After stirring at room temperature for 3 h (monitored by TLC), citric acid was added to adjust the pH to 4. The product was extracted with dichloromethane, dried over Na2SO4 and concentrated to afford 5.1 g (38%) of the title compound (129) as a clear liquid. This material was used in the next reaction without further purification. 1H NMR (CDCl3, 400 MHz): δ 1.55 (s, 3H), 4.03 (m, 4H).

1. washThe organic solution was washed successively with saturated sodium chloride solution (2×80 mL)
2. customThe organic layer was separated
3. concentrationthe combined organic extracts were concentrated
4. additionThe residue was treated with 1N sodium hydroxide at room temperature
5. stirringAfter stirring at room temperature for 3 h (monitored by TLC), citric acid
6. additionwas added
7. extractionThe product was extracted with dichloromethane
8. dry with materialdried over Na2SO4
9. concentrationconcentrated

ORDレコード

ord-a3a7534f04ba4d0383bb7369212bfc8e

出典データセット

uspto-grants-2012_05

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US08168623B2