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

Participants

Reaction Steps

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]+

Provenance & Evidence