Reaction #1470427

Reaction equation

HCl

1-oxyl-2,2,6,6-tetramethyl-4-hydroxypiperidine

HCl

→

1-Hydroxy-2,2,6,6-tetramethyl-4-hydroxypiperidinium Chloride

Solvents

isopropanol

isopropanol

Conditions

Workup

1. 1
   Temperatureby occasionally cooling with an ice bath
2. 2
   Filtrationfiltered
3. 3
   Washwashed with isopropanol
4. 4
   Othergiving a pale yellow solid
5. 5
   Other5.0 g of this crude product is recrystallized from 100 mL isopropanol affording 3 g of a white crystalline solid, mp>260° C.

Procedure

67 mL of isopropanol is cooled to 0° C. and saturated with HCl gas. This solution is added dropwise to a mechanically stirred solution of 50 g (0.29 mol) 1-oxyl-2,2,6,6-tetramethyl-4-hydroxypiperidine in 130 mL of isopropanol, maintaining a reaction temperature of about 20° C. by occasionally cooling with an ice bath. The HCl salt is vacuum filtered and washed with isopropanol, giving a pale yellow solid. 5.0 g of this crude product is recrystallized from 100 mL isopropanol affording 3 g of a white crystalline solid, mp>260° C.

Source