Thiophene, 2-nitro- → Ethyl 7-thienylamino-1H-pyrazolo[4,3-b]pyridine-6-carboxylate

HRID 986745

Reaction equation

HRID 986745 reaction equation
Cl[C:2]1[C:7]([C:8]([O:10][CH2:11][CH3:12])=[O:9])=[CH:6][N:5]=[C:4]2[CH:13]=[N:14][NH:15][C:3]=12.[NH2:16][C:17]1[S:18][CH:19]=[CH:20][CH:21]=1.[N+](C1SC=CC=1)([O-])=O>[Pd]>[S:18]1[CH:19]=[CH:20][CH:21]=[C:17]1[NH:16][C:2]1[C:7]([C:8]([O:10][CH2:11][CH3:12])=[O:9])=[CH:6][N:5]=[C:4]2[CH:13]=[N:14][NH:15][C:3]=12

Participants

5

Reactant 3

HCID 11866Thiophene, 2-nitro-HCID 973732-AminothiopheneHCID 20038759Ethyl 7-chloro-1H-pyrazolo[4,3-B]pyridine-6-carboxylate

Product 1

HCID 20156241Ethyl 7-thienylamino-1H-pyrazolo[4,3-b]pyridine-6-carboxylateYield 10.4%

Reagents, catalysts & solvents 1

HCID 23938PalladiumCatalyst

Procedure

Ethyl 7-chloro-1H-pyrazolo[4,3-b]pyridine-6-carboxylate (4.5 g 0.02 mole) and aminothiophene (2.0 g) [prepared from 2-nitrothiophene (supplied by Aldrich and shown by nmr to contain 15% of 3-nitrothiophene) by reduction using either H2 ; 10% Pd/C or stannous chloride] were stirred together under nitrogen for 24 hours. The ethanol was removed under reduced pressure. The resulting brown oil was purified by column chromatography on silica eluting with 5% methanol/ether to give the title compound as a beige solid (0.600 g), mp 188°-190° C.

Workup

  1. customThe ethanol was removed under reduced pressure
  2. customThe resulting brown oil was purified by column chromatography on silica eluting with 5% methanol/ether

Sources & evidence

ORD record
ord-40304c089c2d43628c76574169abe41e
Source dataset
uspto-grants-1987_12
Patent number
US04716160

Linked notes

Loading…