2-Amino-6-methylpyridine → 2-Amino-6-methylpyridine

HRID 1580942Notes

Reaction equation

HRID 1580942 reaction equation
[NH2:1][C:2]1[CH:7]=[CH:6][CH:5]=[C:4]([CH3:8])[N:3]=1.[S-:9]C#N.[Na+].BrBr>C(O)(=O)C>[NH2:1][C:2]1[CH:7]=[CH:6][CH:5]=[C:4]([CH3:8])[N:3]=1.[NH2:1][C:2]1[C:7]([SH:9])=[CH:6][CH:5]=[C:4]([CH3:8])[N:3]=1

Participants

6

Reactant 3

HCID 157652-Amino-6-methylpyridineHCID 24408BromineHCID 516871Sodium thiocyanate

Product 2

HCID 157652-Amino-6-methylpyridineHCID 122261942-Amino-6-methylpyridine-3-thiol

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent3×

Procedure

The intermediate 2-amino-6-methylpyridine is prepared as follows: To a solution of 68 g. (0.63 mole) of 2-amino-6-methylpyridine in about 500 ml. of glacial acetic acid, cooled to 10°-15° C., is added a mixture of 170.2 g. (2.1 moles) of sodium thiocyanate suspended in about 570 ml. of glacial acetic acid. A solution containing 30.5 ml. of bromine in about 60 ml. of glacial acetic acid is then added, and the mixture is stirred at 10°-15° C. for 1 hour and then at 75°-80° C. for 1/2 hour. The solution is filtered, and the solvent is removed from the filtrate under reduced pressure. The residue is recrystallized from isopropyl alcohol containing activated charcoal. The 2-amino-5-methylthiazolo[4,5-b]pyridine thus obtained melts at 150°-160° C. The product is hydrolyzed by refluxing 8 g. of the material in 120 ml. of 20 percent aqueous sodium hydroxide solution for 6 hours. The resulting cloudy solution is filtered, and the filtrate is acidified and reduced to dryness. The residue is extracted with hot ligroin to yield 2-amino-6-methyl-3-pyridinethiol, melting at 133°-138° C.

Workup

  1. additionis added
  2. additiona mixture of 170.2 g
  3. additionA solution containing 30.5 ml
  4. waitat 75°-80° C. for 1/2 hour
  5. filtrationThe solution is filtered
  6. customthe solvent is removed from the filtrate under reduced pressure
  7. customThe residue is recrystallized from isopropyl alcohol containing activated charcoal
  8. temperatureby refluxing 8 g
  9. waitof 20 percent aqueous sodium hydroxide solution for 6 hours
  10. filtrationThe resulting cloudy solution is filtered
  11. extractionThe residue is extracted with hot ligroin

Sources & evidence

ORD record
ord-221fbcaf92284d9299cb22ee5e3b95d3
Source dataset
uspto-grants-1976_01
Patent number
US03935195

Reaction notes

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