| CPC A61K 8/345 (2013.01) [A61Q 19/00 (2013.01); A61Q 19/007 (2013.01); B01D 3/4205 (2013.01); C07C 29/141 (2013.01); C07C 29/60 (2013.01); C07C 29/80 (2013.01); C07C 29/84 (2013.01); C07C 31/207 (2013.01); A61K 2800/10 (2013.01)] | 20 Claims |

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1. A method for manufacturing 1,3-butylene glycol, which is a method for obtaining purified 1,3-butylene glycol from a crude reaction liquid containing 1,3-butylene glycol, the method comprising:
a dehydration step of removing water by distillation; a high boiling substance removal step of removing a high boiling point component by distillation; and a product distillation step of obtaining purified 1,3-butylene glycol,
wherein in the dehydration step, a dehydration column is used in which a liquid feed containing 1,3-butylene glycol and water with an acetaldehyde content of 1000 ppm or lower and a crotonaldehyde content of 400 ppm or lower is distilled under a condition where a reflux ratio is greater than 0.3 and not greater than 100, and a liquid concentrated with a low boiling point component containing water is distilled off from above a feed plate, and
in the product distillation step, a product column is used in which a 1,3-butylene glycol liquid feed with an acetaldehyde content of 500 ppm or lower and a crotonaldehyde content of 200 ppm or lower is distilled under a condition of a reflux ratio of higher than 0.1, a liquid concentrated with a low boiling point component is distilled off from above a feed plate, and 1,3-butylene glycol is extracted from below the feed plate.
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