Reaktion #1869345

Reaktionsgleichung

5-amino-3-methylisothiazole-4-carbonitrile

isovaleryl chloride

→

N-(4-cyano-3-methyl-isothiazol-5-yl)-3-methyl-butyramide

Ausbeute 88.2%

Lösungsmittel

pyridine

chloroform

CHCl3

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONAfter the completion of the addition the reaction mixture
2. 2
   Waschenwashed with water (200 ml), 2N HCl (600 ml)
3. 3
   TrocknenNaHCO3 (200 ml), brine (200 ml) and dried over Na2SO4Concentration of the CHCl3 layer
4. 4
   Sonstigeprovided the crude product which
5. 5
   Sonstigewas triturated from DCM/hexanes ( 1/10)
6. 6
   Filtrationfiltered off

Vorschrift

To a solution of 5-amino-3-methylisothiazole-4-carbonitrile (method 4) (105.6 g, 0.76 mol) in pyridine (250 ml) at 0° C., isovaleryl chloride (100 g, 0.83 mol) in chloroform (300 ml) was added dropwise. After the completion of the addition the reaction mixture was allowed to warm to r.t. and stirred overnight. The TLC and the MS showed the complete disappearance of the starting material and the reaction mixture was diluted with CHCl3 (600 ml), washed with water (200 ml), 2N HCl (600 ml), satd. NaHCO3 (200 ml), brine (200 ml) and dried over Na2SO4Concentration of the CHCl3 layer provided the crude product which was triturated from DCM/hexanes ( 1/10) and filtered off to isolate N-(4-cyano-3-methyl-isothiazol-5-yl)-3-methyl-butyramide (149.7 g, 88%) as an off-white crystalline solid. 1H NMR (300 MHz) δ 1.04 (d, 6H), 2.18-2.32 (m, 1H), 2.46 (d, 2H), 2.53 (s, 3H), 9.87 (bs, 1H).

Quelle