Urea, organic synthesis development

The marrying of the fields of coordination chemistry, chemotherapy and enzymology was finally spurred on by the advent of modern instrumental and synthetic techniques, and not least by the dramatic developments in organic synthesis, which was born as a discipline in itself in 1828 with Friedrich Wohler s synthesis of urea from ammonium cyanate. In the course of the development of supramolecular chemistry, enormous progress has been made on quantifying the details of receptors with an affinity for guests which fit inside them. The lock and key image especially has suffered... 

Two complementary procedures have been developed for alkylation of secondary amines [11] - both of which involve the use an excess of amine to drive the reaction to completion. The remaining amine was removed from the required tertiary amine using a polymer supported isocyanate 5 as a nucleophilic scavenger (under thermodynamic control) (Table 1 entry 2). The use of this amine scavenger has subsequently been applied in the purification of urea-based libraries prepared by solid-phase organic synthesis [12],... 

Nitrogen-containing organic compounds are ubiquitous in nature and essential to life. They are also important intermediates and products of the chemical and pharmaceutical industries. As a consequence, chemists have developed a plethora of methods for their generation, starting with the first organic synthesis, Wohler s preparation of urea from ammonium cyanate in 1828.1 There are many reports of the formation of carbon-nitrogen bonds by electrophilic animation of carbanions and enolates in the early literature, but development of this method as a useful synthetic tool, especially for asymmetric synthesis, is of more recent date. 

Since 1828 when urea was first synthesized in the lab from cyanic acid and ammonia the development of organic synthesis has seen remarkable innovations and discoveries. Using modem state of the art techniques allows almost any molecule that can exist under normal conditions (and many of those which cannot) to be synthesized. But this near-omnipotence comes with a price. Complex organic molecules often have multiple reactive pathways available under a variety of reaction conditions. In order to develop synthetic transformations that select one specific reactive pathway, chemists have often resorted to supplemental modifications of their starting materials to block non-... 

The development of biochemistry as a subject may be traced to Lavoisier s work on the chemistry of life258 and to Prout and Berzelius.259 The age-old question about the nature of life has left organic chemistry with a legacy of thinking about vitalism which, despite claims to the contrary, is still associated in the popular mind with the synthesis of urea by Wohler in 1828, by which it is alleged vital forces were banished for ever from organic chemistry.260 Yet another article on the Wohler synthesis... 

Only during 17 and 18 centuries, important foundations were laid in many fields of biology. The 19 century observed the development of very crucial concepts, which include the cell theory by Schleiden and Schwaim, Mendel s study of inheritance and Darwin s theory of evolution. The real push to biochemistry was given in 1828 when total s)mthesis of urea from lead cyanate and ammonia was successfully achieved by Wohler who thus initiated the synthesis of organic compound from inorganic compound. Louis Pasteur,... 

Procedures were developed for the synthesis of new types of simple receptors based on substituted 1,8-naphthyridines. These receptors serve as carriers for the transport of biologically important organic substrates (urea, amino acids, hydroxy acids) into cells (1999JIC661, 2001T4987, 2002EJOC4063). 

Synthesis of Urea from CO2. Although urea was the first of the organic compounds to be formed synthetically, its commercial production had to await the development of the synthetic ammonia process. Here the principal product, NH , and a by-product, COi, which constitute the raw materials for urea production, are prepared cheaply. 

This reaction is of particular interest as urea was first obtained in this way by Wohler in 1828. The discovery of this synthesis of urea had a marked effect on the development of organic chemistry. It was the first example of the formation in the laboratory from so-called inorganic compounds of an organic compound produced in the body as the result of the vital force. The reaction by which urea is formed from ammonium cyanate has been shown to be a reversible one. Silver cyanate is precipitated when silver nitrate is added to a solution of urea in boiling water. The reaction has been investigated quantitatively in the study of the law of mass action. 

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