1,3-Butadiene → HCID 85444138, compound

HRID 261241Notes

Reaction equation

HRID 261241 reaction equation
BrBr.[C:3]([O-:6])(=[O:5])[CH3:4].[K+].[CH2:8]=[CH:9][CH:10]=[CH2:11]>C(O)(=O)C>[C:3]([O:6][C:9]([CH3:8])=[C:10]([O:6][C:3](=[O:5])[CH3:4])[CH3:11])(=[O:5])[CH3:4]

Participants

5

Reactant 3

HCID 78451,3-Butadiene3×HCID 24408Bromine3×HCID 517044Potassium Acetate3×

Product 1

HCID 85444138HCID 85444138, compound

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent2×

Conditions

Temperature
123 °C

Procedure

A 5-liter round-bottom flask was fitted with a heating mantle, stirrer, reflux condenser, thermowell, gas inputs and a burette for bromine addition via an electrically heated vaporizer. To the flask was charged 416.8 grams of glacial acetic acid and 98.2 grams potassium acetate. Nitrogen diluent was passed through the vaporizer and above the surface of the liquid at about 1.5 liters per hr. while the contents of the flask were heated to about 123° C. Butadiene was added at a rate of about 4 liters/hr in the vapor phase above the liquid level of the flask. Bromine was slowly added at a rate of about 3 milliliters per hour into the stream of nitrogen diluent, vaporized in the vaporizer and contacted with butadiene in the vapor phase above the liquid level of the flask. The reaction product of bromine and butadiene liquified in the condenser and dropped back into the rapidly stirred liquid phase of potassium acetate and acetic acid whereupon the dibromobutene-2 reacted with potassium acetate to form diacetoxy-2-butene. A total of 63.7 grams of bromine was added in the above-described manner over a five hour period. The temperature of the liquid layer within the flask was maintained about 122° to 126° C. during the reaction. After the addition of bromine was complete, the liquid layer was stirred for about one hour and cooled to ambient room temperature. At this point the products can be separated by distillation. A more rapid means of product analysis is by gas-liquid chromatography (GLC) using a 3.048 m (10 ft) chromatographic column filled with CS-10 packing (Cyanosilicon, Analabs, Inc.) and programed between 150° C. to 220° C. at a rate of 20° C./minute. Approximately 508 grams of effluent was mixed with 35 grams of an internal standard, hexyl acetate, and the stirring stopped to allow all undissolved salts (mainly potassium bromide) to settle. An aliquot sample of the liquid phase was analyzed by GLC as shown:

Workup

  1. customA 5-liter round-bottom flask was fitted with a heating mantle, stirrer
  2. temperaturereflux condenser

Sources & evidence

ORD record
ord-284fff1a2be746b0b8948886419625ed
Source dataset
uspto-grants-1979_08
Patent number
US04164616

Reaction notes

Loading…