Hydrochloric Acid → 5-Amino-4-(2-chlorophenyl)-2-ethylthieno[2,3-b]pyridine

HRID 1885202Notes

Reaction equation

HRID 1885202 reaction equation
[Cl:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1[C:8]1[C:13]([N+:14]([O-])=O)=[CH:12][N:11]=[C:10]2[S:17][C:18]([CH2:20][CH3:21])=[CH:19][C:9]=12.Cl.O.O.[Sn](Cl)Cl.[OH-].[Na+]>C(Cl)(Cl)Cl.O.O1CCOCC1>[NH2:14][C:13]1[C:8]([C:3]2[CH:4]=[CH:5][CH:6]=[CH:7][C:2]=2[Cl:1])=[C:9]2[CH:19]=[C:18]([CH2:20][CH3:21])[S:17][C:10]2=[N:11][CH:12]=1

Participants

8

Reactant 4

HCID 313Hydrochloric AcidHCID 14798Sodium HydroxideHCID 61436Stannous chloride dihydrateHCID 197871684-(2-Chlorophenyl)-2-ethyl-5-nitrothieno[2,3-b]pyridine

Product 1

HCID 197871805-Amino-4-(2-chlorophenyl)-2-ethylthieno[2,3-b]pyridineYield 85.6%

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 6212ChloroformSolventHCID 312751,4-DioxaneSolvent

Procedure

To a mixture of 4-(2-chlorophenyl)-2-ethyl-5-nitrothieno[2,3-b]pyridine (4.0 g), dioxane (25 ml) and conc. hydrochloric acid (12.5 ml) was added tin(II) chloride dihydrate (8.5 g). After stirring at room temperature for one hour, water was added to the mixture, which was made strong alkaline with 6N NaOH and then extraced with chloroform. The extract was washed with water and dried over MgSO4 and the solvent was distilled off. The residue was chromatographed on a silica gel column and eluted with hexane-ethyl acetate (4 : 1). The solvent was distilled off and to the residue was added hexane to obtain 5-amino-4-(2-chlorophenyl)-2-ethylthieno[2,3-b]pyridine (3.1 g, 85.6%) as crystals. The crystals were recrystallized from isopropyl ether to obtain colorless prisms, mp: 87°-88° C.

Workup

  1. washThe extract was washed with water
  2. dry with materialdried over MgSO4
  3. distillationthe solvent was distilled off
  4. customThe residue was chromatographed on a silica gel column
  5. washeluted with hexane-ethyl acetate (4 : 1)
  6. distillationThe solvent was distilled off and to the residue
  7. additionwas added hexane

Sources & evidence

ORD record
ord-dc1486e684ed400faeba6e69bfd3aee3
Source dataset
uspto-grants-1992_09
Patent number
US05143919

Reaction notes

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