Ring compounds reaction

In a research program to explore the possibilities of synthesizing useful polymeric materials from silazane (Si-N) containing ring compounds, reactions of the following ring systems were studied ... 

Reaction with ammonia yields 5-cyanotetrazole, a nitrogen heterocychc ring compound. Reactions with alkyl amine, RNH2, yield dialkyloxalamidines RNHC(=NH)CH(=NH)NR with dialkylamine, R2NH, the product is N,N-diaIkylcyanoformamidine ... 

O Neal, H. E., Benson, S. W. Biradical mechanism in small ring compound reactions. J. Phys. Chem. 1968, 72,1866-1887. 

THE BIRADICAL MECHANISM IN SMALL RING COMPOUND REACTIONS. 

The naphthalene ring compounds 405 and 406 are tormed by the inter-molecular reaction of /ti-iodoanisole with diphenylacetylene[280]. 

Intramolecular amination with allylic acetates is used for the synthesis of cyclic alkaloids 175]. Cyclization of 293 affords the six-membered ring compound 294 rather than a four-membered ring. The reaction is particularly... 

The reaction of l,4-bis(trimethylsilyl)-l,3-butadiyne (174) with disilanes, followed by treatment with methylmagnesium bromide, produces i,l,4,4-tetra(-trimethylsilyl)-l,2,3-butatriene (175) as a major product[96]. The reaction of octaethyltetrasilylane (176) with DMAD proceeds by ring insertion to give the six-membered ring compounds 177 and 178[97], The l-sila-4-stannacyclohexa-2,5-diene 181 was obtained by a two-step reaction of two alkynes with the disilanylstannane 179 via the l-sila-2-stannacyclobutane 180[98],... 

Several 4-amino-2,5-disubstituted thiazoles (257) have been obtained recently (702, 756, 776, 814, 820) by a ring cyclization reaction of halogeno compounds with cyanamide derivatives (263) according to the general Scheme 135. 

Nylon 6, 11, and 12. This class of polymers is polymerized by addition reactions of ring compounds that contain both acid and amine groups on the monomer. 

The rather special status of five- and six-membered rings is already familiar from organic chemistry. Because of the general stability associated with rings of this size, both reactions (5.EE) and (5.FF) are expected to be less favored when the ring compounds have this size, that is, when 1 = 5 or 6. To see the basis for this conclusion, let us consider some of the evidence for stain in cyclic compounds. 

Substituted ring compounds are formed readily by Diels-Alder reactions. 

Bis(benZoxaZol-2-yl) Derivatives. Bis(benzoxazol-2-yl) derivatives (8) (Table 3) aie prepared in most cases by treatment of dicaiboxyhc acid derivatives of the central nucleus, eg, stilbene-4,4Cdicarboxyhc acid, naphthalene-l,4-dicarboxyhc acid, thiophene-2,5-dicarboxyhc acid, etc, with 2 moles of an appropriately substituted o-aminophenol, followed by a ring-closure reaction. These compounds are suitable for the brightening of plastics and synthetic fibers. 

This reaction is used in the synthesis of large-ring compounds. 

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