A Strong, Sterilizable Dialyzing Membrane.

Abstract

The use of dialyzing membranes in chemistry and physics has been long established. In the effort to apply dialysis to bacteriological problems, difficulties were found, principally due to the necessity for sterilization of all materials used, in order to prevent complications arising from the action of bacteria other than those under investigation. One material after another, physically adapted for dialysis, was rejected because it could not be sterilized satisfactorily. Collodion, dissolved in ether and alcohol, and by dexterous manipulation converted into test-tube-like sacs, received much attention from bacteriologists, since sterilization of such sacs is possible, and dialysis rapid. The technique, however, is very exacting; everything must be just right to secure results at all reliable; the collodion tissue is very fragile; and little satisfactory work is known to the writer as having been successfully done in dialyzing bacterial products by this method.The method here to be described is extremely simple. While designed primarily for bacteriological purposes, it may be of interest to chemists and physicists also. The resulting membrane is exceedingly strong; it can be handled, dry or wet, without injury; it may be repeatedly sterilized in boiling water, free steam or steam under pressure, and dialyzes well. It dialyzes less readily than does fresh collodion, which is, however, rather an advantage, for fresh collodion membranes, if not allowed to dry, dialyze so quickly as to suggest leakage,

IMDAF Cycloaddition as a Method for the Preparation of Pyrrolophenanthridine Alkaloids

“…In addition to the carbomethoxy group, the nitro functionality may also serve in this capacity. 2,5-Dinitrofuran ( 40 ) is readily available from 2-nitrofuran by treatment with concentrated nitric acid . Substitution of one of the nitro groups occurs upon reaction of 40 with various heteronucleophiles, presumably by an addition−elimination mechanism …”

Synthesis, Antimalarial Activity, and Molecular Modeling of Tebuquine Analogues

“…The first approach utilized the Ullman reaction and gave low yields of the required intermediate . An alternative approach involved the use of the Hill reaction, and this gave good yields of 3-(4‘-chlorophenyl)-4-hydroxyacetanilide . In spite of the good yields obtained by this route, the starting materials for this synthesis (e.g., sodium nitromalonaldehyde) are not commercially available.…”

“…17 An alternative approach involved the use of the Hill reaction, and this gave good yields of 3-(4′-chlorophenyl)-4-hydroxyacetanilide. 18 In spite of the good yields obtained by this route, the starting materials for this synthesis (e.g., sodium nitromalonaldehyde) are not commercially available. We decided to investigate an alternative approach to 5 from 3-bromo-4-methoxyac- etanilide 19 using the Suzuki reaction 20 of 8.…”

meta-Bridged Aromatic Compounds.

“…The general method was first applied to the preparation of 2,6-disubstituted p-nitrophenols by Hill (33)(34)(35) and later used by Jones and Kenner (38). As shown in Equation (8), condensation of a ketone (containing two -methylene groups in the cases cited) with the sodium salt of nitromalonaldehyde leads directly to the phenol.…”