Acetals halogenation

Sulphur, as sulphide ion, is detected by precipitation as black lead sulphide with lead acetate solution and acetic acid or with sodium plumbite solution (an alkaLine solution of lead acetate). Halogens are detected as the characteristic silver halides by the addition of silver nitrate solution and dilute nitric acid the interfering influence of sulphide and cyanide ions in the latter tests are discussed under the individual elements. 

Die hydrierende Aminierung gelingt in vielen Fallen auch unter Erhalt von Ester-, Acetal-, Halogen-, N-Benzyl-, Hydroxy-Gruppen und des Furan-Ringes. 

CHEMICAL PROPERTIES Combustible incompatible with strong oxidizers, acetates, halogens, thiocyanates and bases reacts with alcohol stable when stored in glass in refrigerator FP (75°C) LFL (2.9%) UFL (not available). 

CHEMICAL PROPERTIES stable when stored in glass containers at 5 C (41 F) can undergo hydrolysis to hydracrylic acid reacts with alcohol incompatible with acetates, halogens, thiocyanates, and thiosulfates FP(74°C, 165°F) LFL/UFL (2.9%, unknown) AT (unknown). 

Incompatibilities and Reactivities Acetates, halogens, thiocyanates, thiosulfates [Note May polymerize upon storage.] ... 

The a-oxyacylation of aldehydes can also be achieved under similar conditions in the presence of a catalytic amount of piperidine [ 103]. Thus, equimolar amounts of aldehydes 122 and acids 123 react upon mild heating in the presence of catalytic amounts of BU4NI and piperidine and TBHP as the terminal oxidant, in ethyl acetate to give a-acyloxy aldehydes 124 in high yields (Scheme 4.64). Several functional groups such as terminal or internal alkenyl, benzyloxy, silyloxy, acetal, halogen and ester are tolerated under these conditions. 

Fourier transform infrared spectroscopy was applied to the study of lac resin, a complex natural resin of insect origin, and some of its derivatives. The results obtained by this method are compared with those from earlier studies that used classical methods of chemical analysis. Experiments include the preparation of hard and soft resins, dewaxed lac, ammoniated lac, lac acetal, halogenated lac, hydrolysed lac, rebuilt lac (rebulac), and the preparation of lac metal salts. It is found that FTIR has several advantages over classical methods, but that FTIR data requires supplementing by other instrumental techniques such as FT-Raman spectroscopy and solid state nuclear magnetic resonance. 21 refs. 

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