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Zaujímavé články:

 

MEDICÍNSKA CHÉMIA

prof. M. Remko: 100 rokov Medicínskej Chémie: článok(pdf)

 

ORGANICKÁ SYNTÉZA

pKa tabuľky (more comprehensive form is here)

 

Protecting groups stability

 

Organic Synthesis Coll Vol on line

 

Drying of Organic Solvents

Various commonly used organic solvents were dried with several different drying agents. A glovebox-bound coulometric Karl Fischer apparatus with a two-compartment measuring cell was used to determine the efficiency of the drying process. Recommendations are made relating to optimum drying agents/conditions that can be used to rapidly and reliably generate solvents with low residual water content by means of commonly available materials found in most synthesis laboratories. The practical method provides for safer handling and drying of solvents than methods calling for the use of reactive metals, metal hydrides, or solvent distillation.

 

FLC (Flash liquid chromatography)

flash chromatography provides a rapid and inexpensive general method for the preparative separation of mixtures requiring only moderate resolution. Even in cases where high resolution is required, preliminary purification by the flash technique allows simplified high-resolution separations without contamination of expensive HPLC columns. Finally, we would like to stress the facts that use of the 40-63 pm silica gel and a pressure- (and not vacuum-) driven flow rate of 2.0 in./min are crucial for successful separations by this method.

NMR Chemical Shifts of Solvents 

 In the course of the routine use of NMR as an aid for organic chemistry, a day-to-day problem is the identification of signals deriving from common contaminants (water, solvents, stabilizers, oils) in less-than-analytically-pure samples. This data may be available in the literature, but the time involved in searching for it may be considerable.