A Grignard reagent prepared from n-heptyl bromide was carbonated with the carbon-1-

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C dioxide liberated from barium carbonate-1-

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C and concentrated sulfuric acid. The octanoic-1-

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C acid was obtained by acidic hydrolysis and purified by extraction. The yield was more than 90%. To analyze the structure and compute the

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C abundance of the octanoic-1-

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C acid

various analysis of MS

IR

1

H-NMR and

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C-NMR were performed. According to the quality demand of the oral drug

the quantitative measurements of some metallic elements had also been carried out.