Reaction #1130535

Reaction equation

4-picoline

acetonitrile

1-bromo-2-[(2-bromoethyl)disulphanyl]ethane

N-methylpyrrolidone

→

expected product

Yield 90.0%

1,1′-(Disulphanediyldiethane-2,1-diyl)bis(4-methylpyridinium)dibromide

Yield 90.0%

Conditions

Workup

1. 1
   workup.ADDITIONis added over 5 minutes
2. 2
   Temperaturethe mixture is cooled
3. 3
   OtherThe solid obtained
4. 4
   Filtrationis filtered off
5. 5
   Washrinsed with 3×200 ml of acetonitrile
6. 6
   workup.DISSOLUTIONdissolved in 800 ml of isopropanol (at reflux)
7. 7
   TemperatureAfter cooling
8. 8
   workup.ADDITION1 l of ethyl ether is added
9. 9
   OtherThe precipitate formed
10. 10
    Filtrationis filtered off
11. 11
    Washrinsed with 3×200 ml of ethyl ether
12. 12
    Otherdried
13. 13
    OtherThe off-white powder obtained (73.77 g)

Procedure

67 g of 4-picoline are diluted in 100 ml of acetonitrile and the mixture is heated to 80° C. A mixture of 60 g of 1-bromo-2-[(2-bromoethyl)disulphanyl]ethane and 15 ml of N-methylpyrrolidone (NMP) is added over 5 minutes. After 4 hours of stirring at 85° C., the mixture is cooled. The solid obtained is filtered off, rinsed with 3×200 ml of acetonitrile and then dissolved in 800 ml of isopropanol (at reflux). After cooling, 1 l of ethyl ether is added. The precipitate formed is filtered off, rinsed with 3×200 ml of ethyl ether and then dried. The off-white powder obtained (73.77 g) contains a great majority (>90%) of the expected product, which is used as it is for the following step.

Source