Phosphorus tribromide → 6-(1-Bromoethyl)-4,4-dimethylchroman

HRID 2118519

Reaction equation

HRID 2118519 reaction equation
[CH3:1][C:2]1([CH3:15])[C:11]2[C:6](=[CH:7][CH:8]=[C:9]([CH:12](O)[CH3:13])[CH:10]=2)[O:5][CH2:4][CH2:3]1.P(Br)(Br)[Br:17]>CCOCC.N1C=CC=CC=1.CCCCCC>[CH3:1][C:2]1([CH3:15])[C:11]2[C:6](=[CH:7][CH:8]=[C:9]([CH:12]([Br:17])[CH3:13])[CH:10]=2)[O:5][CH2:4][CH2:3]1

Participants

6

Reactant 2

HCID 24614Phosphorus tribromideHCID 140102484,4-Dimethyl-6-(1-hydroxyethyl)chroman

Product 1

HCID 140102506-(1-Bromoethyl)-4,4-dimethylchromanYield 83.8%

Reagents, catalysts & solvents 3

HCID 1049PyridineCatalystHCID 3283Diethyl EtherSolventHCID 8058HexaneSolvent2×

Conditions

Temperature
0 °C

Procedure

6.2 g of 4,4-dimethyl-6-(1-hydroxyethyl)chromane were dissolved in 3 ml of absolute ether and 20 ml of hexane and the solution was treated with 3 drops of pyridine. At a temperature of 0°-5° C. there was slowly added dropwise thereto a solution of 5.4 g of phosphorus tribromide in 20 ml of hexane. The mixture was stirred at 0° C. for a further 3 hours, poured onto ice and extracted with ether. The organic phase was washed with dilute sodium bicarbonate solution and water, dried over sodium sulphate and evaporated. There were obtained 4.5 g of 4,4-dimethyl-6-(1-bromoethyl)chromane in the form of a reddish oil which was converted into the phosphonium bromide without further purification.

Workup

  1. additionAt a temperature of 0°-5° C. there was slowly added dropwise
  2. additionpoured onto ice
  3. extractionextracted with ether
  4. washThe organic phase was washed with dilute sodium bicarbonate solution and water
  5. dry with materialdried over sodium sulphate
  6. customevaporated

Sources & evidence

ORD record
ord-b1566a18aafd4e60b56d5a61e499e417
Source dataset
uspto-grants-1987_07
Patent number
US04678793

Linked notes

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