Nitrogen-phenyl

The kinetics of catalysis of cyclotrimerization was studied on the model system phenyl isocyanate/ace-tonitrile (solvent). Acetonitrile (AN, 99.64%, from Vinstron Corp.) was purified by refluxing with phosphorus pentoxide (5 g/1), then with calcium hydride (2 g/1) followed by distillation under nitrogen. Phenyl isocyanate was obtained from the Upjohn Company with a purity of 99.5%, and was purified by distillation. Tolylene diisocyanates (2,4 and 80/20 2,4/2,6 isomers) were obtained from the Mobay Chemical Co., and were purified by distillation. Cyclic sulfonium zwitterions (SZ) were obtained from the Dow Chemical Co. 

Unsaturated Hydrocarbon-Substituted Sulfonamides. N-substituents containing double bonds gave either fast or delayed action at 1% concentration (Table 3). Double bonds directly attached to the nitrogen (phenyl (X) and vinyl (VII)) gave fast kill at 1%, whereas the methylene interrupted allyl (VIII), and benzyl (XI) substituents gave excellent delayed activity. Hie allyl (VIII) analog had Class IV activity. 

This fluorescence arises as a result of excitation in either of two spectral bands. Emission from a single chromophore is observed and the two excitation bands are described in terms of both an intra- and an inter-molecular charge transfer complex (CTC). The intra-CTC is ascribed to rotation around the imide nitrogen-phenyl bond. The inter-CTC arises as a result of the increase in aggregation associated with a more ordered phase. The emission intensity from excitation of the inter-CTC band increases linearly with reciprocal intermolecuar spacing. 

Reactions with Azo Compounds. Meerwein reactions of diazoniiun halides with acrylonitrile take place at low temperatures, catalyzed by cupric chloride, to yield 2-halo-3-arylpropionitriles. Reactions with diazomethane compoimds lead to pyrazolines and finally cyclopropanes. Reactions with 9-diazofluorene produce a cyanocyclopropane derivative, with the generation of nitrogen. Phenyl azide reacts with acrylonitrile to 5deld a heterocyclic nitrile at room temperature or an open-chain nitrile at elevated temperatures. 

A con jugated sp - -sp --" single bond (for example, the bond joining the tw o phenyl rings of biphenyl, the central bond of butadiene, with delocali/ed aromatic bonds, or phenyl amine, where N-G bond is labeled aromatic and nitrogen is sp2 b h ybridi/ed) IS described by a two-fold barrier, V2=l() kcal/mol. 

If preferred, the apparatiaa depicted in Fig. II, 7, 13 may be used. This enables an oxygen-free nitrogen atmosphere to be maintained in the apparatus and leads to the best yield of phenyl-lithium. 

The cyclic carbamate (oxazoIidin-2-one) 313 is formed by the reaction of phenyl isocyanate (312) with vinyloxirane[I92]. Nitrogen serves as a nucleophile and attacks the carbon vicinal to the oxygen exclusively. The thermodynamically less stable Z-isomer 315 was obtained as a major product (10 I) by the reaction of 2-methoxy-l-naphthyI isocyanate (314) with a vinyloxir-... 

Acetylation of 2-phenyl-4-amino-5-benzoylthiazole takes place on the exocyclic nitrogen (49). This exocyclic nitrogen remains the reactive center even with 2-imino-3-aryl-4-amino-5-carboxamido-4-thiazoline (111). Its acetylation with acetic anhydride gives the 4-acetamido derivative (112), which reacts further on heating to yield 2-(acetylimino)-(3H)-3-aryl-5-methylthiazolo[4,5-d]pvrimidin-7-(6H)-one (113) (Scheme 76) (276). 

Treatment of 2-imino-3-phenyl-4-amino-(5-amido)-4-thiazoline with isocyanates or isothiocyanates yields the expected product (139) resulting from attack of the exocyclic nitrogen on the electrophilic center (276). Since 139 may be acetylated to thiazolo[4,5-d]pyrimidine-7-ones or 7-thiones (140). this reaction provides a route to condensed he erocycles (Scheme 92). 

These halogenation reactions all take place in the 5-position (408. 409. 430) even when there is a phenyl or a 2-pyridyl (382) substituent on the exocyclic nitrogen. Crystalline perbromides have been isolated (166. 320. 

The general pattern of alkylation of 2-acylaininothiazoles parallels that of 2-aminothia2ole itself (see Section III.l). In neutral medium attack occurs on the ring nitrogen, and in alkaline medium a mixture of N-ring and N-amino alkylation takes place (40, 43, 161. 163). In acidic medium unusual behavior has been reported (477) 2-acetamido-4-substituted thiazoles react with acetic anhydride in the presence of sulfuric acid to yield 2-acetylimino-3-acetyl-4-phenyl-4-thiazolines (255) when R = Ph. but when R4 = Me or H no acetylation occurs (Scheme 151). The explanation rests perhaps in an acid-catalyzed heterocyclization with an acetylation on the open-chain compound (253), this compound being stabilized... 

The protonation of the nitrogen atom of thiazole induces a large increase in reactivity of the 2-position (193, 194). This is in contrast to the pyridine series, where the reactivity of both positions adjacent to the nitrogen atom are enhanced (194). The phenylation of conjugate acid of 5-alkylthiazoles may then be considered as a preparative route to alkyl-thiazoles. The results (isomer percent and overall reactivity) are indicated in Tables III-31 (196) and 01-32 (196). 

Ecample Suzuki et. al. used a reaction strategy to expand the Cgo molecule, buckminsterfullerene, by adding divalent carbon equivalents. Adding phenyl diazomethane to Cgo. (I)> followed by the loss of molecular nitrogen, results in a Cgi compound. 

Chlorine Ammonia, acetylene, alcohols, alkanes, benzene, butadiene, carbon disulflde, dibutyl phthalate, ethers, fluorine, glycerol, hydrocarbons, hydrogen, sodium carbide, flnely divided metals, metal acetylides and carbides, nitrogen compounds, nonmetals, nonmetal hydrides, phosphorus compounds, polychlorobi-phenyl, silicones, steel, sulfldes, synthetic rubber, turpentine... 

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