Guanidines monosubstituted

The reaction of diacetylene or its monosubstituted homologs with guanidine in the presence of an equimolar amount of sodium ethylate (80°C, EtOH, 14 h) leads to 2-amino-4-alkylpyrimidines (33) (70ZOR1347 71ZOR14). Their structures were proved by comparison of their properties (as well as those of their picrates) with those of authentic samples obtained by independent synthesis. 

Drake, B. Patek, M. Lebl, M. A Convenient Preparation of Monosubstituted yV,yV -di(Boc)-Protected Guanidines, Synthesis 1994, 579-582. 

Kim, K. Lin, Y.-T. Mosher, H. S. Monosubstituted Guanidines from Primary Amines and Aminoiminomethanesulfonic Acid, Tetrahedron Lett. 1988,29, 3183-3186. 

Di(alkyl or aryl)amino-l,2,4-thiadiazoles (90 R,R = alkyl or aryl) are similarly obtainable in 60-85% yields from the appropriate disubstituted amidinothioureas (89 R,R = alkyl or aryl).56,57 The preparation of the latter from monosubstituted guanidines (87) and isothiocyanate esters (88) might conceivably yield the isomeric ami-... 

A modification of this method, which produces 2-aminoimidazoles in up to 90% yield, utilizes benzoins and diguanylhydrazine. The 2,2 -azoimidazoles (123) can be catalytically hydrogenated to the 2-amino compounds (Scheme 66) (66RCR122). When the disubstituted guanidine (124) is treated with phenacyl bromide the first product formed is the expected 2-( l-pyrazolyl)imidazole (125), but subsequent hydrolysis of this occurs to give a 57% yield of l-isopropyl-4-phenylimidazolin-2-one (Scheme 66) (70AHC(12)103). Benzamidine hydrochloride reacts with monosubstituted glyoxals to form 2-imidazolin-4-ones. 

Yl. Yamada, S., and Itano, H. A., Phenanthrenequinone as an analytical reagent for arginine and other monosubstituted guanidines. Biochim. Biophys. Acta 130, 538-540 (1966). 

Guanidine 8 with remote chiral centres, a monosubstituted acyclic guanidine, was prepared by guanidinylation of an amine function with 3,5-dimethylpyrazole-l-carboxamidine [14]... 

Scheme 4.4 Preparationof monosubstituted acyclic guanidine 8 and selected guanidinylating reagents of amines...

Chloro-l,3-dimethylimidazolium chloride (DMC) [26] (R =R = Me, L = H in 11, Scheme 4.8a) not only acts as a powerful dehydration agent but also has unique and versatile abilities to chlorinate primary alcohols, to oxidize primary and secondary alcohols and to reduce sulfoxides and so on. In addition, DMC easily reacts with amines to yield the corresponding guanidines. Thus, methods of preparing monocyclic and bicyclic systems by application of DMC chemistry in the key steps have been developed [27] the reaction of DMC-type chloroamidine compounds with amines for trisubstituted mono-cyclic guanidines [27a] (Scheme 4.8a), the intramolecular cyclization of thiourea derivatives after activation with DMC for monosubstituted or disubstituted monocyclic and bicyclic guanidines [27b] (Scheme 4.8b), and the DMC mediated cyclization of... 

No new synthetic route to monosubstituted 1,3,5-triazines has been reported. The reaction of 1,3,5-triazine with imidates gives monoalkyl- or aryl-l,3,5-triazines <1961JOC2784>. 2-Amino-l,3,5-triazines are best prepared by reaction of triformidomethane with a formyl guanidine <1963AGE655>. 

Blass J. P (1960) The simple monosubstituted guanidines of mammalian brain. Biochem. J 77, 484-489... 

Mid-Determination of Monosubstitut-ed Guanidine as Their Hexafluoro-acetyl Acetone Derivatives... 

Ammonium salts of acids amides of carboxylic and simple sulphonic acids imides aldehyde-ammonias urea, its salts and monosubstitution products many ortho and para aromatic nitro-amines oximes car-bazides nitriles (some feebly) guanidines tMoureaand its mono-substitution products purines (e.g. uric acid). 

Sequential diacylation of 1-guanidinylpyrazole gives the N.N -bis(Boc)-guanidinylpyrazole, which is also an efficient reagent for the conversion of amines to protected monosubstituted guanidines and therefore for the synthesis of arginine-containing peptides from their ornithine counterparts (eq 26). ... 

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