Hydrochloric Acid → 4,5,6,7-Tetrahydrothiazolo[5,4-c]pyridin-2(1H)-one

HRID 249308Notes

Reaction equation

HRID 249308 reaction equation
[S-:1][C:2]#[N:3].[NH4+].Br.C([N:9]1[CH2:14][CH2:13][C:12](=O)[CH:11](Br)[CH2:10]1)(=O)C.Cl.[OH2:18]>>[NH:3]1[C:12]2[CH2:13][CH2:14][NH:9][CH2:10][C:11]=2[S:1][C:2]1=[O:18]

Participants

5

Reactant 4

HCID 313Hydrochloric AcidHCID 962Water2×HCID 15666Ammonium thiocyanateHCID 197611761-Acetyl-3-bromopiperidin-4-one hydrobromide

Product 1

HCID 144238774,5,6,7-Tetrahydrothiazolo[5,4-c]pyridin-2(1H)-oneYield 6%

Procedure

Ammonium thiocyanate (5.54 g, 72.8 mmol) was mixed with water (450 ml) and heated to 80°. A solution of N-acetyl-3-bromo-4piperidone hydrobromide (20.0 g, 66.2 mmol) in water (200 ml) was added dropwise over 3 hours. The reaction was then allowed to stir at 80° for sixteen hours. The reaction solution (containing the crude N-acetyl-3-thiocyanate-4-piperidone) was treated with concentrated hydrochloric acid (6 ml of a 12M solution, 93 mmol) and heated to reflux for 2 hours. The reaction mixture was then freeze-dried, and the residue dissolved in methanol and filtered. The precipitate was purified by column chromatography (eluant: 89:10:1 chloroform:methanol: concentrated ammonium hydroxide) to provide the title product as a white solid, m.p. 208° (decomp.) (0.60 g, 3.8 mmol, 6% yield).

Workup

  1. temperatureheated to 80°
  2. temperatureheated
  3. temperatureto reflux for 2 hours
  4. customThe reaction mixture was then freeze-dried
  5. dissolutionthe residue dissolved in methanol
  6. filtrationfiltered
  7. customThe precipitate was purified by column chromatography (eluant: 89:10:1 chloroform:methanol: concentrated ammonium hydroxide)

Sources & evidence

ORD record
ord-36cf70974c1042ddab5de029d8d6747f
Source dataset
uspto-grants-1993_05
Patent number
US05214051

Reaction notes

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