Sodium Sulfite → Ethyl 3-cyclopropyl-2-oxopropanoate

A solution of ethyl 2-(cyclopropylmethyl)-1,3-dithiane-2-carboxylate (20.8 g, 0.084 mol) in acetone/water (97/3, v/v; 80 mL) was added drop wise over 30 minutes to a stirred suspension of N-bromosuccinimide in acetone/water (97/3, v/v, 1220 mL) at −5° C. The reaction mixture was stirred at the same temperature for 1 hour, while the progress of the reaction was monitored by thin layer chromatography, and then a mixture of methylene chloride/hexane (1/1, v/v, 500 mL) and aqueous sodium sulphite was added. The mixture was stirred until the colour faded from the organic layer. The phases were separated and the aqueous phase was extracted with methylene chloride/hexane (3×300 mL). The combined extracts were washed with aqueous sodium sulfite, water, aqueous sodium bicarbonate, brine and dried over magnesium sulfate. The solvent was removed under reduced pressure to afford ethyl 3-cyclopropyl-2-oxopropanoate (12.3 g, 93.4%), as a light yellow oil. 1H-NMR (400 MHz, CDCl3): δ=0.13-0.21 (m, 2H), 0.54-0.65 (m, 2H), 0.97-1.10 (m, 1H), 1.38 (t, J=8 Hz, 3H), 2.72 (d, J=8 Hz, 2H), 4.33 (q, J=8 Hz, 2H).

1. additionwas added
2. stirringThe mixture was stirred until the colour
3. customThe phases were separated
4. extractionthe aqueous phase was extracted with methylene chloride/hexane (3×300 mL)
5. washThe combined extracts were washed with aqueous sodium sulfite, water, aqueous sodium bicarbonate, brine
6. dry with materialdried over magnesium sulfate
7. customThe solvent was removed under reduced pressure

ORD record

ord-16605f6788b342a1a89c952e7821120e

Source dataset

uspto-grants-2012_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08324417B2