Organic synthesis
This type of reaction scheme involves the individual preparations of several key intermediates, which are then combined to form the desired product.
[12] Before beginning any organic synthesis, it is important to understand the chemical reactions, reagents, and conditions required in each step to guarantee successful product formation.
When determining optimal reaction conditions for a given synthesis, the goal is to produce an adequate yield of pure product with as few steps as possible.
For practical, industrial applications additional reaction conditions must be considered to include the safety of both the researchers and the environment, as well as product purity.
[18] However, in many situations increased heat can cause the solvent to boil uncontrollably which negatively affects the reaction, and can potentially reduce product yield.
Reflux condensers are specially calibrated pieces of glassware that possess two inlets for water to run in and out through the glass against gravity.
This flow of water cools any escaping substrate and condenses it back into the reaction flask to continue reacting[19] and ensure that all product is contained.
Vacuum filtration uses suction to pull liquid through a Büchner funnel equipped with filter paper, which catches the desired solid product.
[15] This process removes any unwanted solution in the reaction mixture by pulling it into the filtration flask and leaving the desired product to collect on the filter paper.
As chemistry has developed methods of stereoselective catalysis and kinetic resolution have been introduced whereby reactions can be directed, producing only one enantiomer rather than a racemic mixture.
[23] Early examples include stereoselective hydrogenations (e.g., as reported by William Knowles[24] and Ryōji Noyori[25]) and functional group modifications such as the asymmetric epoxidation by Barry Sharpless;[26] for these advancements in stereochemical preference, these chemists were awarded the Nobel Prize in Chemistry in 2001.
Using techniques developed by Robert B. Woodward paired with advancements in synthetic methodology, chemists have been able synthesize stereochemically selective complex molecules without racemization.
[1] Each step breaks down the parent structure into achievable components, which are shown via the use of graphical schemes with retrosynthetic arrows (drawn as ⇒, which in effect, means "is made from").
This synthesizer demonstrates the versatility of substrates and the capacity to potentially expand the type of research conducted on novel drug molecules without human intervention.
Examples of common characterization methods include: nuclear magnetic resonance (NMR),[30] mass spectrometry,[31] Fourier-transform infrared spectroscopy (FTIR),[32] and melting point analysis.
[34] In the synthesis of Ibuprofen proposed by Kjonass et al., p-isobutylacetophenone, the starting material, is reduced with sodium borohydride (NaBH4) to form an alcohol functional group.
