Dimethylformamide → 3-(2,4-Dichloro-phenyl)-2,6-dimethyl-pyrazolo[5,1-b]oxazole-7-carbaldehyde

HRID 1671342Notes

Reaction equation

HRID 1671342 reaction equation
O=P(Cl)(Cl)Cl.[Cl:6][C:7]1[CH:12]=[C:11]([Cl:13])[CH:10]=[CH:9][C:8]=1[C:14]1[N:15]2[N:22]=[C:21]([CH3:23])[CH:20]=[C:16]2[O:17][C:18]=1[CH3:19].CN([CH:27]=[O:28])C>>[Cl:6][C:7]1[CH:12]=[C:11]([Cl:13])[CH:10]=[CH:9][C:8]=1[C:14]1[N:15]2[N:22]=[C:21]([CH3:23])[C:20]([CH:27]=[O:28])=[C:16]2[O:17][C:18]=1[CH3:19]

Participants

4

Reactant 3

HCID 6228DimethylformamideHCID 24813Phosphorus oxychlorideHCID 591860073-(2,4-Dichloro-phenyl)-2,6-dimethyl-pyrazolo[5,1-b]oxazole

Product 1

HCID 866389413-(2,4-Dichloro-phenyl)-2,6-dimethyl-pyrazolo[5,1-b]oxazole-7-carbaldehyde

Procedure

To DMF (12 ml) is added POCl3 (1.326 ml, 14.23 mmol) dropwise at RT. After 10 mins 3-(2,4-dichloro-phenyl)-2,6-dimethyl-pyrazolo[5,1-b]oxazole (Intermediate HE) (2.00 g, 7.11 mmol) is added. The reaction is stirred at RT for 16 hours. On cooling to 0° C. the reaction mixture is quenched with 1M HCl and added in portions to sat. Na2CO3 (100 ml). The product is extracted with EtOAc (2×100 ml) and the combined organics are washed with brine, dried over MgSO4 and concentrated in vacuo. The resulting solid is recrystallised from EtOAc/iso-hexane to afford the title compound as a pale yellow solid. MS: m/z 309.10 [M+H]+

Workup

  1. temperatureOn cooling to 0° C. the reaction mixture
  2. customis quenched with 1M HCl
  3. additionadded in portions to sat. Na2CO3 (100 ml)
  4. extractionThe product is extracted with EtOAc (2×100 ml)
  5. washthe combined organics are washed with brine
  6. dry with materialdried over MgSO4
  7. concentrationconcentrated in vacuo
  8. customThe resulting solid is recrystallised from EtOAc/iso-hexane

Sources & evidence

ORD record
ord-a746d318717e4863afa52f1009e7607d
Source dataset
uspto-grants-2011_08
Patent number
US07994203B2

Reaction notes

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