Methyl iodide → (+/-)-3-(2,4-Dichloro-phenyl)-7-(1-methoxymethyl-butoxy)-2,6-dimethyl-pyrazolo[5,1-b]oxazole

Participants

Reaction Steps

To a stirring solution of (±)-2-[3-(2,4-dichloro-phenyl)-2,6-dimethyl-pyrazolo[5,1-b]oxazol-7-yloxy]-pentan-1-ol (60 mg, 0.157 mmol) in THF (1.565 ml) at RT is added NaH (6.26 mg, 0.157 mmol). After 10 mins MeI (10.77 μl, 0.172 mmol) is added and the reaction mixture is stirred for a further 3 hours. An additional 1.leq of MeI (10.77 μl, 0.172 mmol) is added and reaction continued for 1 hour whereupon it is added to sat. ammonium chloride (50 ml) and the product extracted into EtOAc (60 ml). The organics are washed with brine, dried over MgSO4 and concentrated in vacuo. The crude reaction products are purified by ISCO combiflash chromatography, eluting with 0 to 100% (iso-hexane/EtOAc) on a 12 g SiO2-column to give (±)-3-(2,4-Dichloro-phenyl)-7-(1-methoxymethyl-butoxy)-2,6-dimethyl-pyrazolo[5,1-b]oxazole as a solid; MS: m/z 397.20 [M+H]+; 1H NMR (400 MHz, CDCl3) δ 7.58 (2H, m), 7.41 (1H, dd), 4.03 (1H, m), 3.58 (2H, m), 3.44 (3H, s), 2.33 (3H, s), 2.30 (3H, s), 1.76 (2H, m), 1.57 (2H, m), 1.00 (3H, t).

Provenance & Evidence