Reaction #455474

Reaction equation

3-chloro-5-ethynyl-2-methylthiopyridine

1-nitropropane

1,4-phenylenediisocyanate

Water

→

desired product

3-Ethyl-5-(5-chloro-6-methylthio-3-pyridyl)-isoxazole

Solvents

benzene

Conditions

Workup

1. 1
   Temperaturewas heated
2. 2
   Temperatureunder reflux
3. 3
   workup.STIRRINGto stir at room temperature overnight
4. 4
   workup.STIRRINGthe mixture stirred at room temperature for 2 hours
5. 5
   FiltrationIt was filtered through Celite
6. 6
   Dryingdried over anhydrous sodium sulphate
7. 7
   Otherevaporated under reduced pressure
8. 8
   OtherRecrystallisation of the residue from hexane

Procedure

A mixture of 3-chloro-5-ethynyl-2-methylthiopyridine (0.5 g, 2.72 mmol), 1-nitropropane (0.24 g, 0.27 mmol), 1,4-phenylenediisocyanate (1.3 g, 7.93 mmol) and triethylamine (5 drops) in benzene (20 mL) was heated under reflux with stirring for 8 hours, and allowed to stir at room temperature overnight. Water (1 mL) was added and the mixture stirred at room temperature for 2 hours. It was filtered through Celite, dried over anhydrous sodium sulphate and evaporated under reduced pressure. Recrystallisation of the residue from hexane gave the desired product (0.33 g, 48%) as a cream solid, melting point. 78-80° C.

Source