2- -carboxamides

Carboxamides can be cathodically reduced to amines or alcohols, depending on the reaction conditions the reaction is carried out industrially. One example is the reduction of pyridine carboxamides at Reilly 543)  

The reaction can also be used for the stereoselective elimination of protective groups 545) and for the synthesis of amino acid derivatives 546)  

The electrochemical reduction of cyclic imides requires strongly acidic electrolytes, for example, a large excess of H2S04. This leads to large amounts of waste salts during the isolation of the reduction products  

If lactams are initially converted to the corresponding lactim ethers, the inevitable production of waste salts can be substantially reduced  

On the other hand, the reduction of phthalic anhydride to phthalide is simpler. The key step in this synthesis is the electrochemical reduction of ammonium phthalamates 

and Ludwig, R. A. (1962) The Dithiocarbamates and Related Compounds. Elsevier Publishing Comp. Amsterdam, New York. 

Van Logten, M. J. (1972) De dilhiocarbamaat-alcohol reactie bij de rat. Dissertatie, Utrecht. 

Van der Kerk, G. J. M. (1958) Plant Pathol., Problems Progr. 1908-1958. Univ. Wisconsin Press, Madison 6, Wise. (Pub. 1959) p. 280. 

(1975) Chemical Decomposition of Bisdithiocarbamate Fungicides and their Metabolism by Plants and Microorganism. Ph. D. Dissertation, Utrecht. 

and Kaars Sijpesteijn, A. (1971) Pestic. Biochem. Physiol., 1, 163. 

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Alkenes in (alkene)dicarbonyl(T -cyclopentadienyl)iron(l+) cations react with carbon nucleophiles to form new C —C bonds (M. Rosenblum, 1974 A.J. Pearson, 1987). Tricarbon-yi(ri -cycIohexadienyI)iron(l-h) cations, prepared from the T] -l,3-cyclohexadiene complexes by hydride abstraction with tritylium cations, react similarly to give 5-substituted 1,3-cyclo-hexadienes, and neutral tricarbonyl(n -l,3-cyciohexadiene)iron complexes can be coupled with olefins by hydrogen transfer at > 140°C. These reactions proceed regio- and stereospecifically in the successive cyanide addition and spirocyclization at an optically pure N-allyl-N-phenyl-1,3-cyclohexadiene-l-carboxamide iron complex (A.J. Pearson, 1989). 

Another version of the o-aminobenzyl anion synthon is obtained by dilithi-ation of A-f-Boc-protected o-alkylanilines. These intermediates are C-acylated by DMF or A"-methoxy-At-melhyl carboxamides, leading to either 3- or 2,3-disubstituted indoles. In this procedure dehydration is not spontaneous but occurs on brief exposure of the cyelization product to acid[4]. Use of CO as the electrophile generates oxindoles. 

Chlorosulfonyl isocyanate has been used to introduce 3-carboxamide groups. The initial product, an A -chlorosulfonylcarboxamide, is treated with tri-n-butylstannanc to form the primary carboxamide[15], 3-Cyano groups can also be introduced using chlorosulfonyl isocyanate. The intermediate N-chlorosulfonylindole-3-carboxamide is converted to 3-cyanoindole on reaction with triethylamine[16] or DMF[17],... 

The recently reported rearrangement (1581) of 2-allylamino-4-carboxamido-5-aminothiazoIes to 4-aminoimidazole-5-carboxamide in presence of sodium bicarbonate probably involves the electrophilic reactivity of C-2, which allows the ring opening. 

Thiazole carboxamides are readily dehydrated to nitriles in good yields by heating with phosphorus oxychloride (91), phosphorus pentoxide (87, 71), or phosphoryl chloride (16) (Scheme 19). 

Amides. For primary amides the suffix -amide is added to the systematic name of the parent acid. For example, CH3—CO—NHj is acetamide. Oxamide is retained for HjN—CO—CO—NHj. The name -carboxylic acid is replaced by -carboxamide. 

CbHORINE OXYGEN ACIDS AND SALTS - CbHOROUS ACID, CbHORITES, AND CbHORINE DIOXIDE] (Vol 5) [l-(2,6-Diethylphenyl)-imida2ole-5-carboxamide]... 

Acrylamide, C H NO, is an interesting difiinctional monomer containing a reactive electron-deficient double bond and an amide group, and it undergoes reactions typical of those two functionalities. It exhibits both weak acidic and basic properties. The electron withdrawing carboxamide group activates the double bond, which consequendy reacts readily with nucleophilic reagents, eg, by addition. 

A[,A/-diethyl-l,3,4,6,7,ll -hexaliydro-2-hydroxy-9,10-dimethoxy-2Ff-ben2o-(i7)-quinoli2ine-3-carboxamide acetate hydrochloride) (16) may be made by the method described in Reference 14. 

Specialty Isocyanates. Acyl isocyanates, extensively used in synthetic appHcations, caimot be direcdy synthesized from amides and phosgene. Reactions of acid haUdes with cyanates have been suggested. However, the dominant commercial process utilizes the reaction of carboxamides with oxalyl chloride [79-37-8]. CycHc intermediates have been observed in these reactions which generally give a high yield of the desired products (86). 

The PBRis distinct from the central BZ receptor although both can be present in the same tissues in differing ratios. PBRs are predominately localized on the outer mitochondrial membrane and are thus intracellular BZ recognition sites. The PBR is composed of three subunits an 18,000 mol wt subunit that binds isoquinoline carboxamide derivatives a 30,000 mol wt subunit that binds BZs and a 32,000 mol wt voltage-dependent anion channel subunit. The porphyrins may be endogenous ligands for the PBR. PBRs are involved in the control of cell proliferation and differentiation and steroidogenesis. 

CONH2 amides carbamoyl cyano -amide or carboxamide ... 

Table 3 gives the corresponding physical properties of some commercially important substituted pyridines having halogen, carboxyHc acid, ester, carboxamide, nitrile, carbiaol, aminomethyl, amino, thiol, and hydroxyl substituents. 

Pyridinecarbonitriles, -carboxamides, and -carboxylic Acids. 3-Cyanopyridine (25) is used for the production of niaciu (27), or vitamin 4-Cyanopyridine (15) is used for making the antitubercular dmg isonia2id (31) (101). 

Sixty-two novel experimental carboxamides of 1,2,3,6-tetrahydropyridine have been tested as repellents of German cockroaches, and five provided 100% repeUency for 17 d in a stringent test (48). 

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