Reaction #2267058

Reaction equation

Sodium hydroxide

2-methylpentyl methanesulphonate

ethanol

2-mercapto-1,3,4-thiadiazole-5-amine

→

required product

2-(2-Methylpentylthio)-1,3,4-thiadiazole-5-amine

Solvents

ethyl acetate

Conditions

Workup

1. 1
   TemperatureThe mixture was heated
2. 2
   Temperatureto reflux
3. 3
   Temperatureat reflux over night
4. 4
   TemperatureAs the mixture warmed the cream suspension
5. 5
   workup.DISSOLUTIONgradually dissolved
6. 6
   TemperatureJust before refluxing
7. 7
   Otherformed
8. 8
   Filtrationfiltered
9. 9
   Washthe residue was washed well with ethanol
10. 10
    ConcentrationThe resulting filtrate was concentrated to dryness
11. 11
    Otherto give an off-white solid
12. 12
    Washwashed with 1) water (800 mL) and 2) brine (1 L)
13. 13
    DryingThe filtrate was dried (MgSO4)
14. 14
    Concentrationconcentrated to dryness
15. 15
    OtherAn off-white solid was obtained
16. 16
    Otherthat was recrystallised
17. 17
    WashThe filtered material was washed well with acetonitrile
18. 18
    Otherdried (Vac/40° C.)

Procedure

A three-necked 3-L round bottom flask was charged with 2-methylpentyl methanesulphonate (90 g, 0.5 mol), ethanol (1.5 L) and 2-mercapto-1,3,4-thiadiazole-5-amine (66.5 g, 0.5 mol). Sodium hydroxide (20 g, 0.5 mol) was added to the stirred suspension. The mixture was heated to reflux and held at reflux over night. As the mixture warmed the cream suspension gradually dissolved. Just before refluxing began a cloudy precipitate formed. The reaction mixture was cooled to room temperature, filtered, and the residue was washed well with ethanol. The resulting filtrate was concentrated to dryness to give an off-white solid that was dissolved in ethyl acetate (1.2 L) and washed with 1) water (800 mL) and 2) brine (1 L). The filtrate was dried (MgSO4) and concentrated to dryness. An off-white solid was obtained that was recrystallised from boiling acetonitrile (150 mL). The filtered material was washed well with acetonitrile and dried (Vac/40° C.). The required product was obtained as a white solid wt 83 g; 76.5%.

Source