Barbiturates

5,5-diethylbarbituric acid. C ₈ H ₁₂ N ₂ O ₃ (184.20). Diethyl malonate is treated with ethyl bromide, then urea is heated in the presence of sodium ethylate to form the sodium salt, which is then neutralized with hydrochloric acid to obtain this. White needle-like crystals. Odorless, slightly bitter. Melting point: 188-192 °C. Dissolves in water, hot water, and ethanol. A long-acting barbituric acid derivative hypnotic drug with a depressant effect on the central nervous system. It is addictive, and chronic poisoning with withdrawal symptoms occurs after 2-3 months of continuous use of 0.8-1.0 g. Other side effects include nausea, headache, and lethargy. It is sold commercially under the trade names Veronal, Barbitone, and Malonal. Phenobarbital, in which the ethyl group is replaced by a phenyl group, has four times the hypnotic effect of barbital. [CAS 57-44-3]

Source: Morikita Publishing "Chemical Dictionary (2nd Edition)" Information about the Chemical Dictionary 2nd Edition

5,5-diethylbarbituric acid．C₈H₁₂N₂O₃(184.20)．マロン酸ジエチルに臭化エチルを作用させたのち，尿素をナトリウムエチラート存在下で加熱し，ナトリウム塩とし，これを塩酸で中和すると得られる．白色の針状晶．無臭で，わずかに苦味を呈す．融点188～192 ℃．水，熱水，エタノールに溶解する．バルビツル酸誘導体の長時間作用型睡眠薬で，中枢神経系に対する抑制作用がある．習慣性を有し，0.8～1.0 g を2～3か月連続使用すると禁断症状を伴う慢性中毒となる．そのほか，吐き気，頭痛，無気力感などの副作用もある．ベロナール，バルビトーン，マロナールなどの商品名で市販されている．エチル基がフェニル基に置き換わったフェノバルビタールは，バルビタールに比べて4倍の催眠作用をもつ．[CAS 57-44-3]

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