Hydrochloric Acid → Methyl 2,2-dimethylbutanoate

Temperature

-20 °C

Anhydrous diisopropylamine (11.5 g, 0.114 mol) was dissolved in anhydrous THF (50 ml) under argon atmosphere. To the mixture stirred at -20° C. was added dropwise n-butyl lithium (1.62N, 70 ml, 0.114 mol) over 30 minutes, then a solution of isobutyric acid (5.0 g, 0.057 mol) in anhydrous THF (10 ml) was added dropwise over 30 minutes, and further a solution of ethyl bromide (6.2 g, 0.057 mol) in anhydrous THF (10 ml) was also added dropwise over one hour. Aqueous hydrogen chloride (6N) was added to adjust pH to 2 near 0° C. The reaction mixture was extracted with ethyl acetate (50 ml×2). The ethyl acetate layers were washed with water (20 ml×1) and with brine (20 ml×1), dried over anhydrous sodium sulfate and concentrated. The residue was dissolved in ether (30 ml) and an excess of an ethereal solution of diazomethane was added. Distillation under an atmospheric pressure gave 2,2-dimethyl-butanoic acid methyl ester (5.3 g, 0.046 mol, yield 80.2%, b.p.=115°-120° C.) as a colorless clear liquid. The structure was identified by the following data.

1. customto adjust pH to 2 near 0° C
2. extractionThe reaction mixture was extracted with ethyl acetate (50 ml×2)
3. washThe ethyl acetate layers were washed with water (20 ml×1) and with brine (20 ml×1)
4. dry with materialdried over anhydrous sodium sulfate
5. concentrationconcentrated
6. dissolutionThe residue was dissolved in ether (30 ml)
7. additionan excess of an ethereal solution of diazomethane was added
8. distillationDistillation under an atmospheric pressure

ORD record

ord-f65547fdf4b044218d6201b7bdf6fc87

Source dataset

uspto-grants-1988_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04775692