3-Amino-substituted derivatives

The use of guanidine for cyclization gives amino substituted derivatives (e.g. 212) (52CB1012), and in this case o-aminonitriles may be used to furnish diamines (e.g. 8UOC1394). An unusual reaction involving nitriles occurred during the preparation of nicotinonitrile from the amide and ammonium sulfamate, when a 60% yield of the dimeric by-product (213) was formed via the nitrile (69BSB289). Similar products have been obtained from... 

The molecular structures of 39c,e in the crystals show that the B-B and B-C distances of the C2B3 frameworks are considerably shorter than those of boron-amino-substituted derivatives [56], which are described as bicyclo-organoboranes. 

Liu M, Xie C, Xu W, Lu WY. Separation of polyethylene glycols and their amino-substituted derivatives by high-performance gel filtration chromatography at low ionic strength with refractive index detection. Journal of Chromatography A 1046, 121-126, 2004. 

Firefly luciferin is an example of an azole that contains a benzene ring fused to the five-membered ring. Such structures are fairly common. Another example is benzimidazole, present as a structural unit in vitamin B12. Some compounds related to benzimidazole include purine and its amino-substituted derivative adenine, one of the so-called heterocyclic bases found in DNA and RNA (Chapter 28). 

Aniline is the parent IUPAC name for amino-substituted derivatives of benzene. Substituted derivatives of aniline are numbered beginning at the carbon that bears the amino group. Substituents are listed in alphabetical order, and the direction of numbering is governed by the usual first point of difference rule. 

Quinazolines are of great interest in the pharmaceutical industry as protein tyrosine kinase inhibitors. Dener et al 8 described a synthesis starting from 2-methoxybenzaldehyde, Wang, or Rink resins. With the aldehyde resin reductive aminations were undertaken to yield polymer-bound secondary amines (Fig. 7). The latter were subjected to 2,4-dichloro-6,7-dimethoxyquinazoline to give the 4-amino-substituted derivatives. These were then allowed to react with primary or secondary amines at 135-140° in the presence of DBU in DMA. As a result of a detailed scope and limitation study, Dener et al,28 note that some bifunctional amines, such as piperazine, give to some extent dimeric derivatives. 

No simple salts of 2,1 -benzisothiazole have been described in the literature, other than those of amino-substituted derivatives,101 in which the site of protonation is probably the cyclic nitrogen atom, at least in the 3-substituted compounds. The parent compound does, however, form a simple crystalline nitrate 114 which is not very stable. A number of complex salts with platinum, gold, lead, and mercury salts and with picric acid have been described.96,97,116 The picrate is highly crystalline and stable, and is useful for the isolation and characterization of 2,1-benzisothiazole. Many substituted 2,1-benzisothiazoles form similarly useful picrates.106... 

The synthesis of the series of 2,4,5-amino-substituted derivatives of 1-phenoxy-anthraquinone (II) was accomplished by an exchange of chlorine or bromine atoms upon heating the corresponding 1-chloro- or 1-bromoanthraquinones in a phenol-phenoxide solution as well as by alkylation of 1-aminomethyl- or dimethylanthra-quinones using methyliodide.14... 

E. P. Fokin, S. A. Russkikh, and L. S. Klimenko, About photochromic properties of amino-substituted derivatives of 1-arylhydroxyanthraquinones, Izv. Sib. Otd. Akad. NaukSSSR, Ser. Khim. NaukN9, 117-124(1979) (Russ.). 

Cyclic voltammograms of unsubstituted arenes usually exhibit irreversible oxidation waves. Often, the introduction of heteroatoms enhances both donor ability and stability (due to better charge delocalization) of the corresponding cation radicals. The electrochemical behavior of amino-substituted derivatives 15 [41], 16 [42], and 17 [43] can serve as representative examples. Thus compound 15 oxidizes extremely easily at a potential as low as -0.2V (two-electron process), whereas compound 16 oxidizes at higher potentials, but in two one-electron steps El = 0.29 V,... 

Amino-substituted derivatives 108b-d are formed via 1,3-oxazetines 109b-d from substituted cyanoamides and HFA (53, 53a, 140). 

The most biologically active /(-lactams are a-amino substituted derivatives (9), which according to Hegedus retrosynthetically derive from amino carbene complexes of type 10 and cyclic imines (11) (Scheme 4). 

The situation is completely different for the amino-substituted derivative II, where the HOMO refers to the rtpp-orbital (bj), whereas the HOMO-1 and HOMO-2 correspond to aj and b2 orbitals. This result has relevance for the coordination behavior of the C-amino-functionalized diphosphirenylium ion II toward the [W(CO)s] moiety. According to calculations at the B3LYP/DZ(P) level the 77 -complex is by 3.8 kcal moH more stable than the isomeric 7] -complex. Fixation of cation II to the metal carbonyl fragment in the 77 -mode leads to an elongation of the P-P bond from 2.11 to 2.31 A. In the complexed ligand CN and PC separations of 1.32 and 1.80 A are calculated <1999EJI1479>. 

The elimination-addition pathway proposed for the epoxidation reaction in the synthesis of flavipucine has been challenged on the grounds that this mechanism has not been established unequivocally. Sesbanine is a novel cytotoxic alkaloid occurring in the seeds of Sesbania drummondiv, its constitution (48) has been settled by spectral study and by X-ray diffraction analysis. Several amino-substituted derivatives of mimosine, (possible inhibitors of the growth of wool) have been synthesized. ... 

Only a few reports deal with the synthesis of 2,3-dihydro-5//-l,4-dithiepins. Thus, reaction of enynes (237) with ethanedithiol gave the amino-substituted derivatives (238) <84URPi 109401, 88ZOR88), and the syntheses of compounds (239) <71UC904>, (240) <85IZV2066>, and (241) <79JCS(Pl)323> have been reported. 

Sialic acids are a group of carbohydrates that have the interesting structural feature of being amino-substituted derivatives of a nine-carbon ketose. A -Acetylneuraminic acid can be considered the parent. 

Readily available 3-bromoisothiazole-5-carbonitriles 118 bearing various C-4 substituents react with either pyrrolidine or morpholine to give, in most cases, the 3-amino-substituted derivatives 119 in high yields (14T7092). 

Our previous results showed that the isomer ratio depended on the steric bulkiness of the substituents on silicon, however, we have not observed such a complete regioselectivity before (4). For the amino-substituted derivatives, the regioselectivity was amplified not only by the steric bulkiness but also by an electronic property of the amino groups. 

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