Water → Methyl 4-bromo-3-oxobutanoate

Temperature

0 °C

22.7 kg of methyl acetoacetate was dissolved in 113.3 kg of 1-chlorobutane and cooled to 0° C. To this mixture was added dropwise 31.4 kg of bromine at 5° C. over 2 hours, and the mixture was thereafter kept at that temperature for 8 hours. The reaction mixture was cooled to −10° C. and added dropwise to 22.7 kg of water at a temperature 10° C. or less in 2 hours, then washed and separated to give an organic layer. The obtained organic layers were concentrated under reduced pressure at a temperature of 40° C. or less to give 42.0 kg of crude methyl 4-bromoacetoacetate. The gas chromatography analysis indicated that the content of methyl 4-bromoacetoacetate in the crude product was 65.3% (27.4 kg, 72% yield), wherein the content of 1-chlorobutane was 19.7%.

1. temperatureThe reaction mixture was cooled to −10° C.
2. washwashed
3. customseparated
4. customto give an organic layer
5. concentrationThe obtained organic layers were concentrated under reduced pressure at a temperature of 40° C. or less

ORD record

ord-55d5d0e8b951452096992e186ae7ac8b

Source dataset

uspto-grants-2002_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06469200B1