Reaktion #1869322

Reaktionsgleichung

5-amino-3-methylisothiazole-4-carbonitrile

isovaleryl chloride

→

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

Ausbeute 79.0%

Lösungsmittel

CHCl3

pyridine

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONAfter the completion of the addition the reaction mixture
2. 2
   Waschenwashed with water (200 mL), 2N HCl (225 mL)
3. 3
   TrocknenNaHCO3 (200 mL), brine (200 mL) and dried over Na2SO4
4. 4
   SonstigeConcentration of the CHCl3 layer provided 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) (6.38 g, 45.9 mmol) in pyridine (20 mL) at 0° C., isovaleryl chloride (6.65 g, 55 mmol) 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 (200 mL), washed with water (200 mL), 2N HCl (225 mL), satd. NaHCO3 (200 mL), brine (200 mL) and dried over Na2SO4. Concentration 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 (8.1 g, 79%) 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