Diethylbarbiturate veronal

The condensation of 1 mol of ethyl malonate with two mols of ethyl iodide in the presence of two mols of sodium ethoxide gives a good yield of ethyl diethylraalonate. Upon allowing the latter to react with the theoretical quantity of urea in the presence of an alcoholic solution of sodium ethoxide, veronal (diethylbarbituric acid or diethylmalonylurea) is produced. 

Diethylbarbituric acid. In a dry 250 ml. distilling flask, fitted with a thermometer reaching to within 3-4 cm. of the bottom and a condenser, place 51 g. of clean sodium and add 110 g. (140 ml.) of super-dr ethyl alcohol (Section 11,47,5). When all the sodium has reacted, introduce 20 g. of ethyl diethylmalonate and 7 0 g. of dry imea (dried at 60 for 4 hours). Heat the flask in an oil bath and slowly distil off the ethyl alcohol. As soon as the temperature of the liquid reaches 110-115°, adjust the flame beneath the bath so that the contents of the flask are maintained at this temperature for at least 4 hours. Allow the flask to cool somewhat, add 100 ml. of water and warm until the solid (veronal-sodium) dissolves. Pour the solution into a beaker, and add a further 100 ml. of water but containing 7 0 ml. of concentrated siilplmric acid this will hberate the veronal from the sodium derivative. The veronal usually crystallises out if it does not, add a few more drops of dilute sulphuric acid until the solution is acid to Congo red. Heat the contents of the beaker, with stirring and the addition of more water if necessary, until all the veronal dissolves at the boiling point. Allow the hot solution to cool, filter off the crystals of veronal and diy in the air. The yield is 12 g., m.p. 190°. 

Barbital (diethylbarbituric acid, Veronal) HEPPS (EPPS. 4-(2-hydroxyethyl)-l-piperazin-propanesulfonic acid)... 

Problem 16.55 Barbiturates are sedative-hypnotic varieties of 5,5-dialkyl substituted barbituric acids. Write the reaction for the formation of Veronal (5,5-diethylbarbituric acid) from the condensation of urea with diethylmalonic ester. [See Problem 17.13(a)]. ... 

The researchers Joseph von Mering and Emil Fischer, a student of von Baeyer, developed the first barbiturate drug to be marketed. Fischer produced 5.5-diethylbarbituric acid, a hypnotic (medication to help patients sleep) and sedative (medication to relax people with constant nervousness and anxiety). This sedative/hypnotic drug was known by the trade names Barbital, Veronal, and Dorminal. Barbital proved to be a more effective sedative/hypnotic agent and replaced the class of drugs, sedative bromides, which were used at the time.14... 

Veronal—Trade name for 5.5-diethylbarbituric acid, a hypnotic/sedative drug produced by Emil Fischer. 

Barbital , diethylbarbituric acid, is sold under the trade name Veronal . It is the oldest of the long-acting barbiturates and is derived through diethyl malonate. 

Each buffer system is generally applicable over a limited range, viz., about 2 units of pH, but by making suitable mixtures of acids and acid salts, whose pfca values differ from one another by 2 units or less, it is possible to prepare a universal buffer mixture by adding a pre-deter-mined amount of alkali, a buffer solution of any desired pll from 2 to 12 can be obtained. An example of this type of mixture is a system of citric acid, diethylbarbituric acid (veronal), boric acid and potassium dihydrogen phosphate this is virtually a system of seven acids whose exponents are given below. 

Barbiturates are all derived from barbituric acid, first obtained from uric acid and synthesized in Germany by Dr. Adolf van Baeyer in 1864. Conrad and Guthzeit synthesized the first barbiturate, 5,5-diethylbarbituric acid (barbital) in 1882. In 1903, Emile Fischer and Baron Josef von Meiing introduced barbital into clinical medicine under the trade name Veronal . Phenobarbital, which has remained the model T of barbiturates, first appeared on the market in 1912 as Luminal . Unfortunately, intoxication with barbiturates is qualitatively similar to intoxication with alcohol and produced similar problems of abuse. 

Figure 7.25 Steric repulsion between a large substituent on melamine leads to curved assemblies between melamines and diethylbarbituric acid ( — Veronal 10). ...

It is often preferable for physiological purposes to use buffer systems other than the boric acid-borate mixtures. L. Michaelis has found that mixtures of veronal (diethylbarbituric acid) with its sodium salt show a satisfactory buffer action in the neighborhood of pH = 8.0. Pure commercial samples of the sodium salt of veronal are readily available, and may be used frequently without previous recrystallization. Buffer mixtures can be prepared by adding hydrochloric acid to the salt. This compound is water-free, and should suffer no loss in weight when dried at 100°. A 0.1 N solution in water requires exactly an equivalent quantity of 0.1 N hydrochloric acid when neutralized against methyl red. A stock solution should contain 10.30 g. of the sodium salt per 500 c.c. Only carbon dioxide free water should be used. 

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