Reaction #435602

Reaction equation

2-Hydroxynicotinic acid

oleum

→

title compound

Yield 83.0%

2-Hydroxy-5-sulfonicotinic acid

Yield 83.0%

Conditions

Workup

1. 1
   Otherto 82° C
2. 2
   TemperatureAfter maintaining this temperature for 12 hrs the reactor contents
3. 3
   Filtrationfiltered
4. 4
   Filtrationre-slurried with acetone (33 Kg) at room temperature, filtered
5. 5
   Otherdried

Procedure

2-Hydroxynicotinic acid (27 Kg, 194.2 mol) was added portionwise to 30% oleum (58.1 Kg) at 50° C. over 1 hr. This caused an exotherm to 82° C. The reaction mixture was heated further to 140° C. After maintaining this temperature for 12 hrs the reactor contents were cooled to 15C and filtered. The filter cake was then re-slurried with acetone (33 Kg) at room temperature, filtered and dried to afford the title compound (35.3 Kg, 83%) as a white solid. Decomposition pt 273° C. δ (DMSOd6): 7.93 (1H, d), 8.42 (1H, d). m/z (Found:220 [M+H]+, 100%. C6H6NO6S requires 220.17).

Source