Bi derivatives

In forcing conditions with excess of reagents the 5,8-bis derivative was obtained in the above cases, with hydrazine and with sulfur nucleophiles. Other authors have also observed selective reactions in the pyrido[2,3-[Pg.242]

Luminescence studies revealed that compounds (119)-(121) displayed broad emission bands at 298 K, with ranging from 387 nm to 371 nm for the P to Bi derivatives, respectively [92]. On cooling to 77 K, compound (119) displays both a fluorescent band nm) and a phosphorescent... 

In order to gain a better insight into these problems, a fundamental study of simple mono- and di-urethanes of the furan series was undertaken. This included the determination of their structure, properties and stability (35) and the mechanism and kinetics of their formation. The combinations investigated were furan alcohols and diols with aliphatic, aromatic and furanic isocyanates and the latter mono- and bis- derivatives with aliphatic and arylalkyl alcohols and diols. The furanic isocyanates prepared included 9 and those given below ... 

Bismuth derivatives Oxides (Bi203, Bi204 and Bi2Os) and hydroxide Bi(OH)3 Organic salts of Bi Copper compounds and carbon black (Soot) further enhance the effect of Bi derivatives [242, 243]. 

While at first glance the structures of the Sb and Bi homologues appear similar to that of As(Et2Dtc)3, closer inspection shows a pseudododecahedral coordination arising from intermolecular M-S interactions at 3.389(4) and 3.210(5) A in the Sb and Bi derivatives, respectively (542). 

Bis(benzeneazoxy)-azoxybenzene Bis(pbenylazoxy) azoxybenzene (called 4.4 -Bis-benzolazoxy-azoxy-benzol in Ger), [CgH5(N20).CBH4.]2(N20) mw 438.43, N 19.17%. The 4,4 -Bis deriv exists in two forms higher melting form, golden-yel crysts (from benz or petr eth), mp ca 230°, becomes a thick, viscous liq dec at 265° and lower melting form, copper-red flakes(from benz), mp 223°. 

For multisubstrate enzymatic reactions, the rate equation can be expressed with respect to each substrate as an m function, where n and m are the highest order of the substrate for the numerator and denominator terms respectively (Bardsley and Childs, 1975). Thus the forward rate equation for the random bi bi derived according to the quasi-equilibrium assumption is a 1 1 function in both A and B (i.e., first order in both A and B). However, the rate equation for the random bi bi based on the steady-state assumption yields a 2 2 function (i.e., second order in both A and B). The 2 2 function rate equation results in nonlinear kinetics that should be differentiated from other nonlinear kinetics such as allosteric/cooperative kinetics (Chapter 6, Bardsley and Waight, 1978) and formation of the abortive substrate complex (Dalziel and Dickinson, 1966 Tsai, 1978). 

Bis derivatives 44 (n 0,1) were prepared from 2-mercapto-2-methyl-... 

When two molecules of a Mannich base react together with the formation of a methylenc-bis-derivative (255, Fig. 96), a particular type of C-alkylation lakes place, simultaneously involving deaminomethylation and amine replacement, which could be defined as a self-condensation of the Mannich base. 

Only a few examples of side reactions involving other types of Mannich bases are reported in the literature. In particular, the formation of methylene-bis-derivatives of the substrate (path d in Fig. 30) has been observed in phenolic, - C-heterocyclic, "- and alkylsulfone- -" Mannich bases. 

Both the above mechanisms are proposed in the literature with Mannich bases of nitroalkanes the substitution is clearly favored by the steric hindrance of the amine moiety, thus suggesting path 1, - whereas NMR studies on the reaction of P-amino-ketones with hydroxy coumarins do not reveal the presence of vinyl ketone intermediates. lodomethylated phenolic Mannich bases arc also claimed to react according to path 2, although the formation as by-products of dimers and methylene-bis-derivatives accounts for the participation of methylenequinone intermediates in the process. "... 

By considering the above facts it is not surprising that XPS has only limited application in the investigation of organic As-, Sb- and Bi-derivatives. On the basis of the studied molecular systems and the obtained experimental data, papers published in this field can be grouped as follows ... 

Reactions of DBU and isocyanates or isothiocyanates in the presence of cy-anoacetate or malononitrile in dimethylformamide gave 32 (78GEP2640965). Compound 32 (X = O, R = Ph, R = COOMe) was obtained in the reaction of DBU with 2-cyano-3-hydroxy-3-(phenylamino)acrylate (33). 1,4-Diisocyanatobenzene yielded the bis derivative 34. 

Iodomercuri-2 4-diphenyl-selenophene cannot be formed by the action of mercuric iodide and sodium acetate on 2 4-diphenyl-selenophene, or by sodium iodide upon the 5-chloromercuri compound. A 80 per cent, yield is obtained when the mercuri-bis derivative in acetone solution is heated for ten minutes with mercuric iodide. The pure product forms colourless crystals, but imless the experiment is performed in the dark only a red product is isolated. 

Gyanomercuri -2 4 diphenyl - selenophene.—The 5-chloromercuri compound is treated with sodium cyanide in acetone solution. The mercuri-bis derivative is precipitated, and dilution of the filtrate gives a 50 per cent, yield of the 5 cyanomercuri compound, M.pt. 256-4° C. A 90 per cent, yield is obtained when the mercuri-bis derivative is heated for ten nunutes in acetone solution with mercuric cyanide. 

On the action of phosphoryl chloride the 4,5-dihydropyrrolo[l,2-a]quin-azolin-5-one 113 gave the 5-chloro derivative 166 and the bis derivative 173... 

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