Hydrochloric Acid → 4,5,6,7-Tetrahydrothieno(3,2-c)pyridine

HRID 1612936Notes

Reaction equation

HRID 1612936 reaction equation
[CH2:1]1N2CN3CN(C2)C[N:2]1[CH2:9]3.Cl.S(=O)(=O)(O)O.C(O)(=O)C(O)=O.[C:23]1(C)[CH:28]=C[C:26]([S:29](O)(=O)=O)=[CH:25][CH:24]=1.CS(O)(=O)=O.[OH-].[Na+]>C1COCC1.C1(C)C=CC=CC=1.C(O)=O>[S:29]1[C:23]2[CH2:28][CH2:9][NH:2][CH2:1][C:24]=2[CH:25]=[CH:26]1

Participants

11

Reactant 7

HCID 313Hydrochloric AcidHCID 971Oxalic AcidHCID 1118Sulfuric AcidHCID 4101Hexamethylenetetramine2×HCID 6101p-Toluenesulfonic acidHCID 6395Methanesulfonic Acid2×HCID 14798Sodium Hydroxide

Product 1

HCID 30850764,5,6,7-Tetrahydrothieno(3,2-c)pyridine

Reagents, catalysts & solvents 3

HCID 284Formic AcidSolventHCID 1140TolueneSolventHCID 8028TetrahydrofuranSolvent2×

Procedure

The formimine (2) is shaken with a dilute solution of an aqueous acid (such as hydrochloric acid or sulfuric acid) or a solution of formamine (2) dissolved in an organic solvent such as THF or toluene, preferably THF, is shaken with an organic acid (such as formic acid, oxalic acid, paratoluene sulfonic acid or methane sulfonic acid; preferably methane sulfonic acid) for 3 to 10 hours, preferably about 6 hours. The mixture is then basified (e.g., with NaOH) and extracted, e.g., with methylene chloride (or another solvent). The extracts are washed and concentrated in vacuo to give 4,5,6,7-tetrahydrothieno[3,2-c]pyridine (a 80-90% yield of the compound of Formula 3).

Workup

  1. custompreferably about 6 hours
  2. extractionextracted
  3. washThe extracts are washed
  4. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-798d0e3003a74f5fb53fe6b8cf5fcddc
Source dataset
uspto-grants-1993_03
Patent number
US05191090

Reaction notes

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