Ammonium thiocyanate → Methyl 3-Bromo-3-Thiocyanoacrylate
Reaktionsgleichung
[S-:1][C:2]#[N:3].[NH4+].[Br:5][C:6]#[C:7][C:8]([O:10][CH3:11])=[O:9]>S(=O)(=O)(O)O>[Br:5][C:6]([S:1][C:2]#[N:3])=[CH:7][C:8]([O:10][CH3:11])=[O:9]Komponenten
4
Edukt 2
Produkt 1
Reagenzien, Katalysatoren, Lösungsmittel 1
Versuchsvorschrift
To a stirred solution of ammonium thiocyanate (3.06 g., 0.04 mole) in 2M aqueous sulfuric acid (20 ml) at 0° C., methyl 3-bromopropiolate (3.26 g., 0.02 mole) was added dropwise, neat, over 5 minutes. After keeping the temperature at 0° C. for 1 hour, the mixture, consisting of a solid precipitate in the aqueous solution, was extracted with ether which was washed with water, dried (MgSO4), and concentrated. The residual solid was suspended in hexane and removed by filtration, yielding 2.4 g. of product. The solid recrystallized from ethanol as yellowish microcrystals; mp 139°-142.5° C.; IR (KBr) 2170, 1680 cm-1.