Reaktion #604810

Reaktionsgleichung

hexamethylenediamine

Bromoacetaldehyde diethyl acetal

potassium hydroxide

→

N1-(2,2-diethoxyethyl)hexane-1,6-diamine

Lösungsmittel

2-ethyl-1-butanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONadded to the reaction flask
2. 2
   SonstigeA large egg-shaped magnetic stirrer follower was then placed in the flask and its side-arms
3. 3
   Sonstigeconnected to a B24 double-layer coil condenser
4. 4
   Sonstigethe apparatus flushed with a flow of nitrogen gas
5. 5
   SonstigeAs the reaction mixture neared reflux temperature (146° C.)
6. 6
   TemperaturThe reaction mixture was refluxed for a further period of 5 hours under nitrogen before the reaction mixture
7. 7
   Temperaturto cool slowly to room temperature under nitrogen
8. 8
   FiltrationThe reaction mixture was then filtered through a porosity 3 sinter
9. 9
   Sonstigeto remove the KBr that
10. 10
    workup.DISTILLATIONThe 2-ethyl-1-butanol was then stripped from the filtrate by in vacuo distillation at a vacuum pressure of 14 torr and a heating oil bath temperature of 80-100° C
11. 11
    Filtrationthe re-filtration of the concentrated reaction mixture
12. 12
    WaschenThe collected solid was washed with 2×30 mL of diethyl ether
13. 13
    Sonstigea rotary evaporator
14. 14
    workup.DISTILLATIONThe residue in the flask was then fractionally distilled in vacuo through a 30 cm glass column
15. 15
    Sonstige23-36° C. (0.45 torr)
16. 16
    Sonstige36-102° C. (0.35 torr)
17. 17
    Sonstigepredominantly a white solid, unreacted hexamethylenediamine, that solidified in condenser
18. 18
    SonstigeThe apparatus was disassembled at this point so that a clean condenser
19. 19
    Sonstige106-109° C. (0.44 torr)
20. 20
    SonstigeOn completion of the collection of the third fraction collection the apparatus
21. 21
    Temperaturto cool slowly to room temperature overnight under a nitrogen atmosphere
22. 22
    workup.ADDITIONNext day the condenser containing most of the entrained white solid
23. 23
    Sonstigewas substituted for a clean condenser
24. 24
    workup.DISTILLATIONthe distillation
25. 25
    Sonstige112-115° C. (0.60 torr)
26. 26
    workup.ADDITIONcolourless liquid containing a small amount of an entrained white solid

Vorschrift

Into a 1 L 3-neck RB flask was weighed hexamethylenediamine (59.0 g, 508 mmol). To this flask was then added 400 mL of 2-ethyl-1-butanol. Bromoacetaldehyde diethyl acetal (100.1 g, 507.7 mmol) and potassium hydroxide (29.0 g, 517 mmol) were weighed out and added to the reaction flask. A large egg-shaped magnetic stirrer follower was then placed in the flask and its side-arms stoppered with B19 glass stoppers and its centre-socket connected to a B24 double-layer coil condenser which was in turn connected to a nitrogen line and the apparatus flushed with a flow of nitrogen gas. The reaction mixture heated to 165° C. over a period of 30 minutes. As the reaction mixture neared reflux temperature (146° C.) the mixture started boiling quite vigorously indicative of an exotherm taking place and a white precipitate of potassium bromide (KBr) deposited from the solution and the colour of the reaction mixture changed from a pale yellow to an orange colour. The reaction mixture was refluxed for a further period of 5 hours under nitrogen before the reaction mixture allowed to cool slowly to room temperature under nitrogen. The reaction mixture was then filtered through a porosity 3 sinter to remove the KBr that had deposited from the reaction mixture. The 2-ethyl-1-butanol was then stripped from the filtrate by in vacuo distillation at a vacuum pressure of 14 torr and a heating oil bath temperature of 80-100° C. The residue in the distillation flask deposited additional pale yellow precipitate, presumably more KBr, necessitating the re-filtration of the concentrated reaction mixture. The collected solid was washed with 2×30 mL of diethyl ether. The filtrate and washings were combined and the ether component stripped off in vacuo using a rotary evaporator. The residue in the flask was then fractionally distilled in vacuo through a 30 cm glass column packed with 0.5 cm Fenske rings: Fraction 1: 23-36° C. (0.45 torr); a colourless liquid, presumably residual 2-ethyl-1-butanol. Fraction 2: 36-102° C. (0.35 torr); predominantly a white solid, unreacted hexamethylenediamine, that solidified in condenser. The apparatus was disassembled at this point so that a clean condenser could be substituted for that containing the hexamethylenediamine. Fraction 3: 106-109° C. (0.44 torr); colourless liquid which contained some white solid (residual hexamethylenediamine). On completion of the collection of the third fraction collection the apparatus was allowed to cool slowly to room temperature overnight under a nitrogen atmosphere. Next day the condenser containing most of the entrained white solid was substituted for a clean condenser and the distillation was re-started. Fraction 4: 112-115° C. (0.60 torr); colourless liquid containing a small amount of an entrained white solid.

Quelle