Реакция #3995

Уравнение реакции

2,5,9-trimethyl-11-(2,6,6-trimethyl-1-cyclohexen-1-yl)-2,4,6,8,10-undecapentaene-1-ol

triphenylphosphine

N-bromosuccinimide

→

1-methylamino-2,5,9-trimethyl-11-(2,6,6-trimethyl-1-cyclohexen-1-yl)-2,4,6,8,10-undecapentaene

Растворители

THF

Условия реакции

Обработка

1. 1
   workup.ADDITIONAfter addition
2. 2
   Другоеthe cooling bath is removed
3. 3
   Другоеto rise slowly to room temperature
4. 4
   КонцентрированиеThe mixture is concentrated in vacuo
5. 5
   workup.ADDITIONdiluted with a mixture of ether/petroleum ether
6. 6
   workup.WAITAfter sitting in refrigerator for several hours
7. 7
   Фильтрацияwhich is collected by filtration
8. 8
   КонцентрированиеThe filtrate is concentrated
9. 9
   workup.DISSOLUTIONdissolved in 10 ml of dry DMF
10. 10
    workup.ADDITIONTo this solution is added 2 g of triethylamine and 0.68 g of methylamine hydrochloride
11. 11
    workup.ADDITIONpoured into 500 ml of ice-water
12. 12
    ЭкстракцияThe crude product is extracted into ethylacetate
13. 13
    Промывкаwashed with water
14. 14
    СушкаAfter drying over magnesium sulfate
15. 15
    Другоеthe solvent is removed in vacuo
16. 16
    Другоеto give the crude product as an oil
17. 17
    ДругоеThis substance is purified on HPLC (2% ethyl acetate in hexane, silica gel column)

Методика

A solution of 2,5,9-trimethyl-11-(2,6,6-trimethyl-1-cyclohexen-1-yl)-2,4,6,8,10-undecapentaene-1-ol (3.2 g, 10 mmol) and triphenylphosphine (2.88 g, 11 mmol) in 20 ml of THF is stirred in an ice bath and 1.78 g (10 mmol) of N-bromosuccinimide is added in small portions over a period of one hour. After addition, the cooling bath is removed and the temperature of the reaction mixture is allowed to rise slowly to room temperature. The mixture is concentrated in vacuo and then diluted with a mixture of ether/petroleum ether. After sitting in refrigerator for several hours, white crystals of triphenylphosphine oxide occur, which is collected by filtration. The filtrate is concentrated and dissolved in 10 ml of dry DMF. To this solution is added 2 g of triethylamine and 0.68 g of methylamine hydrochloride. The resulting mixture is stirred at room temperature for 18 hours and poured into 500 ml of ice-water. The crude product is extracted into ethylacetate and washed with water. After drying over magnesium sulfate, the solvent is removed in vacuo to give the crude product as an oil. This substance is purified on HPLC (2% ethyl acetate in hexane, silica gel column) to give 1-methylamino-2,5,9-trimethyl-11-(2,6,6-trimethyl-1-cyclohexen-1-yl)-2,4,6,8,10-undecapentaene.

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