Butynediol produced from acetylen(?) and formaldehyde contains about 1% of an unknown byproduct which is separated by distillation, extraction, recrystallization and column chromatography.

• 甲醛炔化制1,4-丁炔二醇的反应副产物中未知物约1%25,采用蒸馏、萃取、重结晶、柱层析等方法分离出未知物,纯度可达97%25左右。