Pyridines amido

In sulfamation, also termed A/-sulfonation, compounds of the general stmcture R2NSO2H are formed as well as their corresponding salts, acid hahdes, and esters. The reagents are sulfamic acid (amido—sulfuric acid), SO —pyridine complex, SO —tertiary amine complexes, ahphatic amine—SO. adducts, and chlorine isocyanate—SO complexes (3). 

The hydrobromide was hydrolyzed to the free base as follows 0.119 kg of 2-(2-bromoacet-amido-5-bromobenzoyl)-pyridine hydrobromide was stirred with 1.2 liters of cold water for 3.5 hours. The mixture was chilled and filtered, and the residue washed with cold water and dried to give 2-(2-bromoacetamido-5-bromobenzoyl)-pyridine, MP 101°C (sinters), 103 -106°C, dec. 

There is obtained from 4-[)3-[5-methyl-isoxazolyl-(3)-carboxamido]-ethyl]-benzene-sulfonamide (prepared from 5-methyl-isoxazole-(3)-carboxylic acid chloride and 4-()3-aminoethyl)-benzene-sulfonamide hydrochloride, MP 213° to 214°C in pyridine) and chloroformic acid methyl ester, in a yield of 69%, the compound N-[ [-4-[)3-[5-methyl-isoxazolyl-(3)-carbox-amido] -ethyl] ] -benzene-sulfonyl] ] -methyl-urethane in the form of colorless crystals of MP 173°C. 

Treatment of the iminoacetate 152 with 4-chlorobenzoyl chloride in the presence of a base gave the desired ethyl 5-(4-chlorophenyl)-l-(2,4-dichlorophenyl)-17/-l,2,4-triazolecarboxylate 153 and the uncyclised ethyl 2-(4-chlorobenz-amido)-2-(2-(2,4-dichlorophenyl)hydrazinyl)acetate 154 in 36% and 6% yield, respectively. The undesired compound 154 was subsequently converted to 1,2,4-triazole 153 in 93% yield by further treatment with pyridine (Equation 47) <2006EJM114>. 

An additional means of performing a selective cross-benzoin was reported in 2001 when Mnrry and co-workers expanded benzoin methodology to include trapping of acyl imines XIX formed in situ (Scheme 6) [53], The authors chose to use a-amido sulfones due to their stability and the relative ease of acyl imine liberation. The parent reaction combines pyridine 4-carboxaldehyde 51 and tosylamide 52 in 98% yield in the presence of pre-catalyst 54 and triethylamine (Scheme 6). 

Numerous d cobalt(III) complexes are known and have been studied extensively. Most of these complexes are octahedral in shape. Tetrahedral, planar and square antiprismatic complexes of cobalt(lII) are also known, but there are very few. The most common ligands are ammonia, ethylenediamine and water. Halide ions, nitro (NO2) groups, hydroxide (OH ), cyanide (CN ), and isothiocyanate (NCS ) ions also form Co(lII) complexes readily. Numerous complexes have been synthesized with several other ions and neutral molecular hgands, including carbonate, oxalate, trifluoroacetate and neutral ligands, such as pyridine, acetylacetone, ethylenediaminetetraacetic acid (EDTA), dimethylformamide, tetrahydrofuran, and trialkyl or arylphosphines. Also, several polynuclear bridging complexes of amido (NHO, imido (NH ), hydroxo (OH ), and peroxo (02 ) functional groups are known. Some typical Co(lll) complexes are tabulated below ... 

With pyridine/S03 complex at higher temperatures (70-80 °C), in addition to sulfation of phenolic, hydroxy, and thiol groups, sulfation of amino, guanidino, and primary amido... 

Andersen prepared the first U amide traHj-[UO2 N(SiMe3)2 2(thf)2] (60) in 1979, from UO2CI2 and 2Na[N(SiMe3)2] in f. The structure of the ciystalline material was confirmed by X-ray data, albeit of poor quality recently a high-quality structure was obtained. The amido groups in 60 were readily displaced by treatment with ArOH and pyridine, yielding [UO2(OAr)2(py)3] (Ar = C6H3P 2-2,6). Reaction of 60 with the macrocyclic compound H4(10) (R = H or Me) resulted in the exclusive formation of the mono-uranyl complex [UO2 H2(10) (thf)] (61). " The latter upon addition of... 

Numerous studies involving similar amido derivatives of metals such as Ti (e.g. heterometallic cross-coupling of benzonitrile with carbon dioxide, pyridine, and benzophenone with mixed [Ti N(Bu )Ar 3] and [Mo N(Bu )Ar 3] systems), V (e.g. denitrogenation of a vanadium nitride by carbon disulfide and dioxide), Nb (e.g. the... 

The amino group of 3-amino-6-benzylidene-6,7,8,9-tetrahydro-ll//-pyrido[2,l-b]quinazolin-ll-one was acylated with ethyl oxalyl chloride in AW-dimethylacetamide in the presence of pyridine at ambient temperature, and the amido group of compound 161 (R = H, R1 = Et) was alkylated with methyl iodide. The ester groups of compounds 161 (R = H, Me, R1 = Et) were hydrolyzed (84GEP3326511). 

Treatment of an a-amino acid with an anhydride in the presence of pyridine, known as the Dakin-West reaction,[1431 gives access to a racemic a-amido ketone.1 44 1451 The mechanism involves formation of an oxazolinone (98)J146 In the modified Dakin-West reaction, the oxazolinone is reacted with an acid chloride (Scheme 33)J136 139] Due to the rapid epimer-ization of the oxazolinones, a diastereomeric mixture of product 99 is obtained. No detailed protocol has been published so far for the modified Dakin-West synthesis applied to (oxomethyleneamino) peptides, but the procedure is adapted from that already reported for (oxomethylene) peptides containing the tp[CO-CH2] link.1147 ... 

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