Réaction #4382

Équation de réaction

hydrogen chloride

n-BuLi

2-iodo-5-methoxy-N,N-dimethylbenzeneethanamine

1-hexyne

→

2-(1-hexynyl)-5-methoxy-N,N-dimethylbenzeneethanamine hydrochloride

Rendement 27.0%

Solvants

Water

tetrahydrofuran

tetrahydrofuran

Conditions de réaction

Traitement

1. 1
   workup.ADDITIONwas added slowly via syringe through a serum
2. 2
   Autrecap
3. 3
   AutreAfter the 20 minutes
4. 4
   TempératureThe second flask was cooled to 0° C
5. 5
   workup.STIRRINGThis solution was stirred for 20 minutes
6. 6
   workup.STIRRINGwas stirred overnight at room temperature under nitrogen
7. 7
   Autrethe organics were evaporated in vacuo
8. 8
   Filtrationthe solid catalyst was filtered off
9. 9
   Autrethe methanol was evaporated in vacuo
10. 10
    workup.ADDITIONMethylene chloride was added to the aqueous residue
11. 11
    Lavagethe organic layer was washed with sodium bicarbonate solution, water, brine solution
12. 12
    Séchagedried over potassium carbonate
13. 13
    AutreThe organics were evaporated in vacuo
14. 14
    Autreto give a red oil
15. 15
    Autregave white crystals which
16. 16
    Autreupon recrystallization from acetonitrile

Mode opératoire

A solution of 2.7 ml (0.027 mole) 1-hexyne in 10 ml dry (4 A sieves) tetrahydrofuran was cooled to 0° C. in an ice bath. Argon was passed over the solution 10.4 ml (0.027 mole) 2.69 M n-BuLi was added slowly via syringe through a serum cap. The resulting solution was stirred 20 minutes under argon. During this time, a second flask containing 3.2 g (0.027 mole) anhydrous zinc chloride was attached to the first flask via cannula. After the 20 minutes the contents of the first flask was transferred to the second flask via cannula. The second flask was cooled to 0° C. This solution was stirred for 20 minutes, then 5 g (0.016 mole) 2-iodo-5-methoxy-N,N-dimethylbenzeneethanamine in 20 ml dry tetrahydrofuran was added via syringe. 0.32 g (mole 1%) tetrakis(triphenylphosphine) palladium was added to the reaction mixture which was stirred overnight at room temperature under nitrogen. Water was added to the reaction mixture and the organics were evaporated in vacuo. The residue was taken up in methanol, the solid catalyst was filtered off and the methanol was evaporated in vacuo. Methylene chloride was added to the aqueous residue, the organic layer was washed with sodium bicarbonate solution, water, brine solution and dried over potassium carbonate. The organics were evaporated in vacuo to give a red oil. Addition of ethereal hydrogen chloride gave white crystals which upon recrystallization from acetonitrile gave 1.27 g (27% yield) of 2-(1-hexynyl)-5-methoxy-N,N-dimethylbenzeneethanamine hydrochloride, mp 145.5°-147.5° C.

Source