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

HRID 2247940Notes

Reaction equation

HRID 2247940 reaction equation
[S-]C#N.[NH4+].Br.C(N1CCC(=O)C(Br)C1)(=[O:8])C.C([N:20]1[CH2:25][CH2:24][C:23](=O)[CH:22]([S:27][C:28]#[N:29])[CH2:21]1)(=O)C.Cl>O>[NH:29]1[C:23]2[CH2:24][CH2:25][NH:20][CH2:21][C:22]=2[S:27][C:28]1=[O:8]

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 15666Ammonium thiocyanateHCID 197611761-Acetyl-3-bromopiperidin-4-one hydrobromideHCID 19816092N-acetyl-3-thiocyanato-4-piperidone

Product 1

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

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

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-4-piperidone 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-thiocyanato-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-39d6f679d89a4baaaf5bcd61f1893f3d
Source dataset
uspto-grants-1991_08
Patent number
US05037834

Reaction notes

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