تفاعل #342096

معادلة التفاعل

urea

2-bromo-4-chloro-6-ethylaniline

HBr

vinylidene chloride

NaNO2

LiBr

→

1-Bromo-2-(2′-bromo-2′,2′-dichloroethyl)-5-chloro-3-ethylbenzene

المردود 83.7%

المذيبات

water

water

acetone

water

ظروف التفاعل

المعالجة

1. 1
   workup.ADDITIONis added dropwise within 15 minutes
2. 2
   workup.ADDITIONTo this mixture is added dropwise, at −10 to −5° C. within 30 minutes
3. 3
   أخرىto come to room temperature
4. 4
   workup.STIRRINGwith good stirring
5. 5
   workup.WAITleft
6. 6
   أخرىto react for another 3 hours
7. 7
   استخلاصextracted twice with 70 ml each time of MTBE
8. 8
   غسيلThe combined organic phases are washed with 30 ml of water
9. 9
   تجفيفdried over sodium sulphate
10. 10
    تركيزconcentrated under reduced pressure

الإجراء التجريبي

At room temperature, 9.38 g [0.04 mol] of 2-bromo-4-chloro-6-ethylaniline are introduced into 30 ml of 36% aqueous HBr, the mixture is cooled to −10 to −5° C., and a solution, cooled to 0° C., of 3.31 g [0.048 mol] of NaNO2 in 15 ml of water is added dropwise within 15 minutes. Subsequently, the mixture is stirred at −10 to −5° C. for 15 minutes. It is then admixed with a solution, cooled to 0° C., of 0.24 g of urea in 75 ml of water, and then 5.36 g [0.024 mol] of copper(II) bromide and 1.74 g [0.02 mol] of LiBr are added. To this mixture is added dropwise, at −10 to −5° C. within 30 minutes, a solution of 67.83 g [0.7 mol=17.5 molar equivalents] of vinylidene chloride in 130 ml of acetone. The mixture is allowed to come to room temperature with good stirring and left to react for another 3 hours. The reaction mixture is diluted with 100 ml of water and extracted twice with 70 ml each time of MTBE. The combined organic phases are washed with 30 ml of water, dried over sodium sulphate and concentrated under reduced pressure. This gives 15.7 g of oil which, according to GC-MS, contains 84.3 area percent (area %) of 1-bromo-2-(2′-bromo-2′,2′-dichloroethyl)-5-chloro-3-ethylbenzene. This corresponds to a yield of 83.7% of theory.

المصدر