Alkylamino groups

It is estimated that mote than 25 x 10 different potentially toxic OP esters can be made using Schrader s classic (27) formula for effective phosphorylating agents, (39), where R and are short-chain alkyl, alkoxy, alkylthio, or alkylamino groups, and X is a displaceable moiety with a high energy P-bond such as E or acyl anhydride, and the pentavalent phosphoms atom is bonded to oxygen or sulfur. 

The type of synthesis in which the two-atom fragment supplies C-5 + C-6 is uncommon but useful in preparing pyrimidine- and 5,6,7,8-tetrahydroquinazoline-2,4-diamines. Thus, dicyandiamide (S78) with benzyl methyl ketone (S77) yields 6-methyl-5-phenylpyrimidine-2,4-diamine (S79), or with acetophenone it yields 6-phenylpyrimidine-2,4-diamine (62JOC2708). Likewise, with cyclohexanone it yields the tetrahydroquinazolinediamine (SSO) and by using N- substituted dicyandiamides, 2- and/or 4-alkylamino groups may be introduced (65JOC1837). 

A few studies on solvolyses by alcohols and by water are available. The hydrolyses studied include displacement of alkylamino groups from acridine antimalarials and of halogen from other systems. In all cases, these reactions appeared to be first-order in the heterocyclic substrate. By a detailed examination of the acid hydrolysis of 2-halogeno-5-nitropyridine, Reinheimer et al. have shown that the reaction rate varies as the fourth power of the activity of water, providing direct evidence that the only reactive nucleophile is neutral water, as expected. 

The influence on the rate of the diverse alkylamino groups relative to NH2 appears to vary over a rather narrow range and involves deactivating factors of 1.4 or less. It is noteworthy that both V-morpho-lino and phenylamino groups are activating and involve maximum factors of 3.1 and 12, respectively. 

As a matter of course, replacement of (cyclo)alkylamino groups with arylamino groups will result in a bathochromic shift. For example, 3 -anilino-6 -chlorofluoran (23)13 develops yellowish red color. 

Alkylamino groups are also employed in place of anilino groups at 2 -position to give black color, though the color tone is a little greenish. These include 6 -diethylamino-3 -methyl-2 -n-octylaminofluoran (60),61 and 3 -chloro-6 -diethylamino-2 -(2-ethoxyethylamino)fluoran (61).62... 

Fluoran compounds have an optically active spiro-carbon atom. Consequently, some fluoran compounds, especially those having an alkylamino group of four or more carbon atoms at 3 -position, have been found to exhibit crystal modifications as determined by X-ray diffraction. Each crystal modification reveals different physical properties such as melting point, solubility, and affinity with acidic compounds, resulting in different characteristics regarding use for carbonless copying papers, thermosensitive recording papers, and the like. 

Substituents such as long-chain alkyl, alkoxy, or alkylamino groups and also sulfonic acid functions tend to increase solubility. 

The flash vacuum thermolyses (600°C) of (disubstituted methylene)-malonates (1716) yielded cyanothioacetates and cyanoacetamides, respectively (1720, R = SMe and NHiPr, NHtBu, NMe2), besides acetone, carbon dioxide, and isobutene or propene (see Scheme 61). In these cases the imidoylketene-to-acylketene imine rearrangement (1717 —> 1718 or 1719 -> 1720) was facilitated by the presence of an electron-rich meth-ylthio or alkylamino group (R1 = SMe and NHiPr, NHtBu, NMe,). 

For some N-Mannich bases of benzamides and various amines, the rate constant increased with the size of the alkylamino group and with the pKa of the free amine. The reactivity also increased strongly with increasing acidity of the parent amide. Thus, N-Mannich bases of toluenesulfonamide or suc-cinimide had tm values of 1 min or less. 

Simple unsaturated sulfides cannot be used in place of enamines in cycloaddition reactions with sulfines leading to thietane dioxide derivatives. " Alkyl, vinyl, and cycloalkylvinyl sulfides, which carry a C=C double bond, are considerably less nucleophilic than the enamines and thus do not partake in cycloadditions to sulfene. But when the more electrophilic methylsulfonyl sulfene is used in association with an unsaturated sulfide substituted with a strong electron donating alkylamino group, the formation of thietane dioxides 72 is successful. 

Teramoto, N., Imanishi, Y, and Yoshihiro, I. (2000). In vitro selection of a ligase ribozyme carrying alkylamino groups in the side chains. Bioconjugate Chem., 11, 744-8. 

A Cu2+ containing linear polymer [77] exhibiting smectogenic behaviour is obtained by a polycondensation technique (Fig. 27). A homologous set of polycondensates of 4,4 -[l,12 dodecanediyl bisfoxy)] bis benzoic acid with bis[AT-[[2,4 dihydrophenyl]methylene]-alkylamino] Cu(II) exhibits monotropic liquid crystalline behaviour with 4—13 carbon atoms in the alkylamino group [78]. 

These are readily prepared by adding amines to trihaloarsines in cooled ether solutions. The reaction proceeds stepwise, halogens being successively replaced by alkylamino groups (equations 3-5). Some examples of dialkylaminoarsines are given in Table 1. 

Along with permethylated derivatives, the permethylated, LiAlH4-reduced derivatives of glycolipids are also used for mass-spectrometric analysis. The amide groups of acetamido sugars and the ceramide part are reduced to alkylamino groups, and, in the case of gangliosides, the ester... 

The azido group was also able to substitute for one of the two alkylamino groups ... 

Zwitterionic cyclodextrins were designed and synthesized by Tabushi a long time ago as artificial receptors for amino acids in water [25]. Only a very low enantioselectivity was detected for Trp. Inoue also studied the complexation of two new P-cyclodextrin derivatives bearing m-toluidinyl and [(9-fluorenyl)-amino]alkylamino groups with various D/L-amino acids by fluorescence spectroscopy in buffered (pH=7.2) aqueous solution. An enantioselectivity as high as 33 was found for D/L-leucine and the former host [26]. 

Thus, one can conclude that the 3-benzylamino group in 311 g as well as ben-zylamine itself is oxidized into their corresponding imines easier than ordinary alkylamines. When both reactants do not contain a benzylamino fragment, the cyclohexylamino group is oxidized first. If both benzylamino and cyclohexylamino functions are absent in the reactants, the process starts from oxidation of a 3-alkylamino group as in 311e,f,k. Heterocyclizations described here represent a novel approach to condensed imidazoles and imidazolines. 

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