Dibutyl bromination

Synthesis and Characterization. Tris(trimethylsilylpropyl)tin fluoride (PTF) and tris(trimethylsilylmethyl)tin fluoride (MTF) were synthesized according to scheme A (Figure 1) while scheme B (Figure 1) was followed in the synthesis of dibutyl-(trimethylsilylpropyl)tin fluoride (BTF). MTF has been reported in the literature (6) however, it was synthesized to compare its solution properties with the other two novel compounds. The steps involved in these syntheses were straight-forward and thus need no elaboration. In the synthesis of BTF, the unsymmetrical triorganotin fluoride, bromination of tetraorganotin compound resulted... 

DIBUTYL CARBITOL (112-73-2) Combustible liquid (flash point 245 F/118°C oc). Reacts violently with oxidizers, permanganates, peroxides, ammonium persulfate, bromine dioxide, sulfuric acid, nitric acid, perchloric acid, and other strong acids. Incompatible with acyl halides, aliphatic amines, alkalis, boranes, isocyanates. Flow or agitation of substance may generate electrostatic charges due to low conductivity. 

A particularly simple method is to brominate (3 moles of Br2 per mole of paraldehyde) paraldehyde in an alcohol, with vigorous stirring and watercooling, this giving bromoacetaldehyde diethyl acetal (72.5%) and dipropyl acetal (65%),645 also bromoacetaldhyde dibutyl acetal (65%) and diisopropyl acetal (22 %).646... 

Benzyl trimethyl ammonium chioride Bismuth, subsalicylate trans-1,2-Bis (n-propylsulfonyl) ethene Bromine p-Chioroaniiine 4-Chloronitrobenzene Chlorophene Climbazole Dibutyl adipate 4,6-Dinitro-o-s-butylphenol ammonium salt 1,4-Dioxane Fenarimol Glyceryl-o-monochlorohydrin ... 

A ketene intermediate is not required in order to generate the P-lactam. In the case of 2.111, ketene formation is not possible. Reaction of the acid chloride with the imine, however, generates an intermediate where the nitrogen can displace the bromine moiety to give the lactam. The reaction of 2.111 and 2.115 proceeded, in the presence of pyridine, to give 2.772.55 Reaction with HCl gave 2,2-diethyl-3-aminopropanoic acid, 2.113. Similarly, 2,2-dipropyl and 2,2-dibutyl-3-aminopro-panoic acids were prepared from the appropriate acid chloride and 2.110. ... 

Bromination of dibutyl vinylboronate at low temperature readily affords a stable di-bromo derivative [2, 3]. Similarly, ( )-alkenylboronic acids or their catechol esters yield the corresponding substituted compound by stereospecific trans addition of bromine. Treatment with base induced anti elimination of the boronic group and the bromine ion. The final result of this sequence was the replacement of boron by bromine with inversion of olefin geometry in excellent yields and 99% stereochemical purities (Scheme 9.1) [4]. 

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