Diaminoalkanes

The high reactivity of N-H bonds has also been exploited to produce N-F denvatives without significant substitution on neighbonng C-H bonds, Diethyl-phosphoramidates of ammonia, alkylammes, and a,polar solvents to produce difluoroamine [57], N,N-difluoroalkylamines, and a,to-bis(At,7V-difluoroamino)alkanes [52] Acetamide undergoes fluonnation to give modest yields of N,N difluoroacetatnide and acetyl fluonde when fluorinated... 

Various heterocyclic structures, among them 3-substituted-hexahydro-277-pyrimido[l,2- ]pyrimidin-2-ones 190, have been prepared by solid-phase synthesis. The acetates 187 were reacted with diaminoalkanes, the resulting diamines 188 cyclized with BrCN to the monocyclic compounds 189, which were cleaved and cyclized with Et3N to give 190 (Scheme 30) <2005TL5289>. 

Bis(bromomethyl)quinoxalines 263 was treated with aldehydes 264 to obtain 265 . Macrocyclization to 266 was completed by cyclocondensation of the aldehydes 265 with the appropriate diaminoalkanes. Elwahy used this chemistry to synthesize new macrocyclic ligands containing the quinoxaline subunit. 

Figure 3.71 Through-bond (TB) splitting Ae = e —e+ for idealized all-trans diaminoalkanes NH2—(CH2)m—NH2, m = 1-4 (29-32), compared with through-space NH3 NH3 interaction in relative geometry of m = 4 (TS-4).

As might have been anticipated, diamines are still more basic than amines, particularly if the added proton may occupy a site in which it is effectively bound to both amino groups. Thus, 1,4- and 1,5-diaminoalkanes have exceptionally high PAs (ca 1000 klmol-1)165. 

In the conversion of 3,4,5,6-tetrabromo-l,2-bis(bromomethyl)benzene into the tetrabromoisoindole (Scheme 5.4), the bisalkylation of the primary amine in the First step of the reaction is promoted by the addition of benzyltrimethylammonium methoxide [22]. 2-Chloromethylpyridine reacts with a series of a,co-diaminoalkanes, as well as 1,2-diaminobenzene, to produce Af V -dialkylated and N,N,N N -tctra-alkylated products [23]. 

According to mass spectrometric studies by Bigler and Hesse (1995), a,(i)-diaminoalkane cation-radicals undergo intramolecular hydrogen atom rearrangements leading to the formation of distonic cation-radicals ... 

Rhizobactin 1021 (Fig. 15, 56) (for rhizobactin, see diaminoalkane-based siderophores, Sect. 3.1) from Rhizobium meliloti (281), contains an acetyl and an ( )-decenoyl group. Its Fe " complex in aqueous solution is A-configured and forms an equilibrium between a monomeric and a dimeric form that can be separated by chromatography. A synthesis is described (404). 

Halogen-substituted T,2, 3, 4 -tetrahydro-l-naphthyl-1,4,5,6-tetrahydropyri-midines, such as (XCVll), and their non-toxic water-soluble salts, are useful as hypotensive agents [681] 2-(p-Aminophenyl)-l,4,5,6-tetrahydropyrimidines (XCVlll), prepared from p-aminobenzoic acid ester and a,co-diaminoalkanes, are active as local anaesthetics over a wide pH range [682]. 

The use of suspended substrates proved very useful in the production of arginine-based surfactants. In this two-step procedure, one amino group of a diami-noalkane was acylated with Z-Arg [55]. This step was done in a melted phase constituted by substrates, and quantitative yields were observed without a catalyst present. Subsequently, the second free amino group of the diaminoalkane reacted with an Z.-Arg-alkyl ester (kinetic control). This step was performed in aqueous suspension or organic solvent using trypsin as the catalyst [73]. 

The reaction of Zr(OCHMe2)4-HOCHMe2 with dibasic ONNO-tetradentate Schiff base ligands derived from diaminoalkanes and salicylaldehyde, 2-hydroxy-l-naphthaldehyde, acetyl-... 

The condensation of an a-diketone or its synthetic equivalent (e.g. aroyl cyanide (87S914)) with a 1,2-diaminoalkane gives 2,3-dihydropyrazines (Scheme 41), which like their 2,5-analogues can be oxidized by air, or better by Mn02 in ethanolic KOH, to pyrazines (78MI21400). 

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