Quinuclidine N-oxide: a potential replacement for HMPA

Abstract

The use of quinuclidine N-oxide as a replacement for HMPA is described.

References

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14. Alkylation of methyl 3-nitropropanoate: A solution of diisopropylamine (0.9 ml, 0.63 mmol) and quinuclidine N-oxide (1.78 g, 14 mmol) in dry THF (40 ml) was cooled to –78 °C. To this solution was added BuLi (4.0 ml, 1.6 M in hexane, 0.63 mmol). The solution was stirred for 30 min, then methyl 3-nitropropanoate (0.37 g, 2.8 mmol) was added. After stirring for 60 min benzyl bromide (0.4 ml, 0.35 mmol) was added. The solution was stirred for 5 h. Acetic acid (1.0 ml, 2.8 mmol) was added followed by distilled water (5.0 ml). The solution was warmed to room temperature and water (50 ml) was added. Diethyl ether (50 ml) was added, the organic layer separated and the aqueous layer extracted with diethyl ether (3 × 50 ml). The combined organic layers were washed with water (100 ml), and dried over MgSO₄. The solvent was removed in vacuo. The crude reaction mixture was purified by flash chromatography over silica gel eluting with EtOAC–light petroleum (bp 40–60 °C), 1 ∶ 9 to give the desired product (0.48 g, 78%). The aqueous layer contains the quinuclidine N-oxide.