Primary amines acylation

Transglutaminases can recognize a broad range of primary amine acyl-acceptor substrates in vitro. However, recognition of the acyl-donor substrate in vivo is restricted to the y-carboxyamide of glutamine within an apparently relatively small subset of sequence contexts... 

The one-pot, three-component synthesis of 1,2,4-triazoles from primary amines, acyl hydrazines and dimethoxy-A(-A(-dimethylmethanamine [84] was utilized for the preparation of compounds 235 (Scheme 41), which were evaluated for their anticonvulsant and neurotoxic properties [85]. The anticonvulsant activity was measured in mice by the maximal electroshock test (MES) and the neurotoxicity in mice by the rotarod neurotoxicity test (Tox). The majority of the compounds... 

Protein glutamine-y-glutamyl transferase (transglutaminase, TGase) catalyzes the acyl transfer between the y-carboxyamide group of peptide-bound glutamine (acyl donor) and primary amines (acyl acceptor, I in Formula 2.114), e. g., peptide-bound lysine (II in Formula 2.114). Free... 

Give the isocyanide (carbylamine) reaction, if the anilide is an acylated primary amine. 

The product of this reaction is an imide (Section 20 16) a diacyl derivative of an amine Either aqueous acid or aqueous base can be used to hydrolyze its two amide bonds and liberate the desired primary amine A more effective method of cleaving the two amide bonds is by acyl transfer to hydrazine... 

AC2O, 18-crown-6, Et3N, 98% yield. The crown ether forms a complex with a primary amine, thus allowing selective acylation of a secondary amine. 

The Cunius degradation of acyl azides prepared either by treatment of acyl halides with sodium azide or trimethylsilyl azide [47] or by treatment of acyl hydrazides with nitrous acid [f J yields pnmarily alkyl isocyanates, which can be isolated when the reaction is earned out in aptotic solvents If alcohols are used as solvents, urethanes are formed Hydrolysis of the isocyanates and the urethanes yields primary amines. 

These Br nsted-type plots often seem to be scatter diagrams until the points are collated into groups related by specific structural features. Thus, p-nitrophenyl acetate gives four separate, but parallel, lines for reactions with pyridines, anilines, imidazoles, and oxygen nucleophiles.Figure 7-4 shows such a plot for the reaction of trans-cmmm c anhydride with primary and secondary aliphatic amines to give substituted cinnamamides.All of the primary amines without substituents on the a carbon (R-CHi-NHi) fall on a line of slope 0.62 cyclopentylamine also lies on this line. If this line is characteristic of normal behavior, most of the deviations become qualitatively explicable. The line drawn through the secondary amines (slope 1.98) connects amines with the structure R-CHi-NH-CHi-R. The different steric requirements in the acylation reaction and in the model process... 

Ac2NOMe selectively acylates a primary amine of a spermidine. ... 

Preparation of the key tropine is achieved by any one of several variations on the method first developed by Robinson, which involves reaction of a primary amine with dihydroxyacetone and glyoxal. Reduction of the carbonyl group in the product (86) followed by acylation affords the aminoester (88). Transesterification with ester aldehyde 89... 

Pi peridinobenzimidazole also serves as starting material for the antipsychotic agent halopemide (69). In the absence of a specific reference, one may speculate that the first step involves alkylation with bromochloro-ethane to give halide The chlorine may then be converted to the primary amine by any of several methods such as reaction with phthalimide anion followed by hydrazinolysis. Acylation with j -fluorobenzoyl chloride then gives the desired product. 

Carboxylic acid derivatives can be converted into primary amines with loss of one carbon atom by both the Hofmann rearrangement and tire Curtius rearrangement. Although the Hofmann rearrangement involves a primary-amide and the Curtius rearrangement involves an acyl azide, both proceed through similar mechanisms. 

Where direct nitration results in degradation, a primary amine can be acylated, nitrated directly to form a secondary niiramine, which is then hydrolyzed to form the primary nitramine as exemplified in the following reaction sequence ... 

Normally ethyl acetate is used for the acylation of primary amines, in many cases, as acyl donor and solvent. Other acylating agents such as alkyl methoxy acetates are... 

The treatment of acyl halides with ammonia or amines is a very general reaction for the preparation of amides.The reaction is highly exothermic and must be carefully controlled, usually by cooling or dilution. Ammonia gives unsubstituted amides, primary amines give A-substituted amides, and secondary amines give N,N-disubstituted amides. Arylamines can be similarly acylated. In some cases aqueous... 

Even though formic anhydride is not a stable compound (see p. 714), amines can be formylated with the mixed anhydride of acetic and formic acids (HCOO-COMe) °°° or with a mixture of formic acid and acetic anhydride. Acetamides are not formed with these reagents. Secondary amines can be acylated in the presence of a primary amine by conversion to their salts and addition of 18-crown-6. ° The crown ether complexes the primary ammonium salt, preventing its acylation, while the secondary ammonium salts, which do not fit easily into the cavity, are free to be acylated. 

As in the Japp-Klingemann reaction, when Z is an acyl or carboxyl group (in the case of R2CH—Z), it can be cleaved. Since oximes and nitroso compounds can be reduced to primary amines, this reaction often provides a route to amino acids. As in the case of 12-4, the silyl enol ether of a ketone can be used instead of the ketone itself. Good yields of a-oximinoketones (20) can be obtained by treating ketones with fert-butyl thionitrate. ... 

The method is not restricted to secondary aryl alcohols and very good results were also obtained for secondary diols [39], a- and S-hydroxyalkylphosphonates [40], 2-hydroxyalkyl sulfones [41], allylic alcohols [42], S-halo alcohols [43], aromatic chlorohydrins [44], functionalized y-hydroxy amides [45], 1,2-diarylethanols [46], and primary amines [47]. Recently, the synthetic potential of this method was expanded by application of an air-stable and recyclable racemization catalyst that is applicable to alcohol DKR at room temperature [48]. The catalyst type is not limited to organometallic ruthenium compounds. Recent report indicates that the in situ racemization of amines with thiyl radicals can also be combined with enzymatic acylation of amines [49]. It is clear that, in the future, other types of catalytic racemization processes will be used together with enzymatic processes. 

Bauerle and Seelig [395] studied the structural aspects of amlodipine (weak base, primary amine pKa 9.26 [162]) and nimodipine (nonionizable) binding to phospholipid bilayers, using NMR, microcalorimetry, and zeta-potential measurements. They were able to see evidence of interactions of amlodipine with the cis double bond in the acyl chains. They saw no clear evidence for (=P—O- 1 H N—) electrostatic interactions. 

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