Hydrochloric Acid → 2-(4-Chlorophenyl)thieno[2,3-d]pyridazin-7(6H)-one

HRID 2239329Notes

Reaction equation

HRID 2239329 reaction equation
[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[S:12][C:11]([C:13](O)=[O:14])=[C:10]([CH:16]=O)[CH:9]=2)=[CH:4][CH:3]=1.O.[NH2:19][NH2:20].Cl.C([O-])(O)=O.[Na+]>C(O)C>[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[S:12][C:11]3[C:13](=[O:14])[NH:19][N:20]=[CH:16][C:10]=3[CH:9]=2)=[CH:4][CH:3]=1

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 24654Hydrazine hydrate (1:1)HCID 516892Sodium BicarbonateHCID 593044065-(4-Chlorophenyl)-3-formylthiophene-2-carboxylic acid

Product 1

HCID 115798042-(4-Chlorophenyl)thieno[2,3-d]pyridazin-7(6H)-oneYield 72.7%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Conditions

Temperature
82 °C

Procedure

To a stirred solution of 5-(4-chlorophenyl)-3-formylthiophene-2-carboxylic acid (3 g, 0.011 mol) in ethanol (30 ml) was added hydrazine hydrate (0.65 ml, 0.013 mol) in small drops. To this was added conc. HCl (1.8 ml, 0.058 mol) in a dropwise manner and heated to 82° C. for 2 days. The reaction mixture was allowed to cool down and 10% NaHCO3 (5 ml) was added slowly until pH=8. The solid was filtered, washed with water (200 ml) and dried to afford 2.1 g (71%) of the title compound. Rf=0.5 (CHCl3:MeOH, 8:2). 1H NMR (400 MHz, DMSO-d6) δ 12.98 (bs, 1H), 8.39 (s, 1H), 7.98 (s, 1H), 7.88 (d, 2H, J=8.6 Hz), 7.59 (d, 2H, J=8.6 Hz).

Workup

  1. temperatureto cool down
  2. filtrationThe solid was filtered
  3. washwashed with water (200 ml)
  4. customdried

Sources & evidence

ORD record
ord-54844651b2ae45009d9a509b1740fa2e
Source dataset
uspto-grants-2010_05
Patent number
US07723331B2

Reaction notes

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