Sodium Bicarbonate → Ethyl alpha-oxobenzenebutanoate

Temperature

5 °C

A 500 ml flask was charged a solution dissolving 41.6 g (200 mmol) of 2-hydroxy-4-phenylbutyric acid ethyl ester in methylene chloride (100 ml) and 148.8 g (purity 12%, 240 mmol) of sodium hypochlorite, and cooled at 5° C. To the reaction mixture was added 86 mg (0.4 mmol) of 4-acetoxy-2,2,6,6-tetramethylpiperidinyl-1-oxy and further added 3.02 g (36 mmol) of sodium hydrogen carbonate. The gradual exothermal reaction proceeded, and the starting material of 2-hydorxy-4-phenylbutyric acid ethyl ester was disappeared in 1.5 hours. The reaction was terminated by adding 100 ml of 5% sodium thiosulfate aqueous solution and was separated. The organic phase was washed with 50 ml of 5% sodium thiosulfate aqueous solution and then 100 ml of 1% sodium carbonate aqueous solution, followed by the removal of the solvent by a rotary evaporator. The residue was subjected to distillation under reduced pressure to obtain 40 g of 2-keto-4-phenylbutyric acid ethyl ester having a boiling point of 103° C. at 0.3 mmHg. The yield was 92%.

1. additionA 500 ml flask was charged a solution
2. customThe gradual exothermal reaction
3. customThe reaction was terminated
4. additionby adding 100 ml of 5% sodium thiosulfate aqueous solution
5. customwas separated
6. washThe organic phase was washed with 50 ml of 5% sodium thiosulfate aqueous solution
7. custom100 ml of 1% sodium carbonate aqueous solution, followed by the removal of the solvent by a rotary evaporator
8. distillationThe residue was subjected to distillation under reduced pressure

ORD record

ord-076e4c5f9c6e473db068dafbd4eee52b

Source dataset

uspto-grants-1992_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05118833