2-Aminopyridine → 6-Aminopyridine-3-sulfonic acid

HRID 990245Notes

Reaction equation

HRID 990245 reaction equation
[NH2:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][N:3]=1.[OH:8][S:9](O)(=[O:11])=[O:10].O=S(=O)=O>>[NH2:1][C:2]1[CH:7]=[CH:6][C:5]([S:9]([OH:11])(=[O:10])=[O:8])=[CH:4][N:3]=1

Participants

3

Reactant 2

HCID 104392-AminopyridineHCID 24681Fuming sulfuric acid

Product 1

HCID 4595336-Aminopyridine-3-sulfonic acidYield 75.2%

Conditions

Temperature
140 °C

Procedure

2-Aminopyridine (80 g, 0.85 mol) was added portionwise over 30 minutes to stirred oleum (320 g) and the resulting solution heated at 140° C. for 4 hours, then allowed to cool. The reaction mixture was poured onto stirred ice (200 g) and this mixture stirred at ice-salt bath temperature for a further 2 hours. The resulting suspension was filtered, then the collected solid washed successively with ice-water (200 ml) and cold industrial methylated spirit (IMS) (200 ml) and, finally, dried under suction to provide the title compound (111.3 g, 75%) as a solid. LRMS: m/z 175 (M+1)+.

Workup

  1. temperatureto cool
  2. additionThe reaction mixture was poured
  3. filtrationThe resulting suspension was filtered
  4. washthe collected solid washed successively with ice-water (200 ml) and cold industrial methylated spirit (IMS) (200 ml)
  5. customfinally, dried under suction

Sources & evidence

ORD record
ord-41f0861307234cf8a23efeec409ae706
Source dataset
uspto-grants-2002_10
Patent number
US06458951B2

Reaction notes

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