Hydrazo compounds table

Hydrazobenzene, 628, 629, 632 conversion into benzidine, 633 Hydrazo compounds, 1074 table of, 1085 ... 

Types of compounds are arranged according to the following system hydrocarbons and basic heterocycles hydroxy compounds and their ethers mercapto compounds, sulfides, disulfides, sulfoxides and sulfones, sulfenic, sulfinic and sulfonic acids and their derivatives amines, hydroxylamines, hydrazines, hydrazo and azo compounds carbonyl compounds and their functional derivatives carboxylic acids and their functional derivatives and organometallics. In each chapter, halogen, nitroso, nitro, diazo and azido compounds follow the parent compounds as their substitution derivatives. More detail is indicated in the table of contents. In polyfunctional derivatives reduction of a particular function is mentioned in the place of the highest functionality. Reduction of acrylic acid, for example, is described in the chapter on acids rather than functionalized ethylene, and reduction of ethyl acetoacetate is discussed in the chapter on esters rather than in the chapter on ketones. 

Compounds of these ions do not occur frequently in the lists of thermodynamic data some of the few results available are given in Table VII. The dissociation constants of hydrocyanic, hydrazoic, cyanic, thiocyanic, and selenocyanic acids are in the approximate ratios 1 10 10 10 10 (123). Some thermodynamic functions of these acids have been obtained, but no attempt was made to confirm that the latter three acids were indeed the N-bonded compounds and that the X-bonded isomers were absent (123). Hydrogen bonding between these acids and various bases has been studied but will not be considered further in this review (see, e.g., Refs. 68 and 362, and references therein). Some electronegativities are also included in Table VII of the cases quoted, only Huheey (394) considered both possible atoms and he assumed -tri di di hybridization in each case. 

Although hydrazoic acid is a weak acid and is probably unable to protonate the hetero atom of the activating groups listed, hydrogen bonding may occur and this would result in mild catalysis of the Ad process. This is illustrated for a, -unsaturated carbonyl compounds equation (73). The examples in Table 5 include reactions in... 

This procedure has found wdde application in the synthesis of aromatic and heteroaromatic azides the yields are usually high and often quantitative. General procedures have been developed by Smith and co-workers the method of choice mainly being determined by the basicity of the amine involved or the solubility of its salts. Weakly basic amines, for example, are diazotized with amyl nitrite in an acetic acid-concentrated sulphuric acid mixture and aqueous sodium azide is subsequently added. Amines which form insoluble salts with common mineral acids zu e converted to the more soluble 2-hydroxyethanesulphonic acid salts prior to diazotization. This procedure has been applied in the diazotization of the N-(aminophenyl)phthalimides (254). Treatment of the resulting diazonium compounds (255) with hydrazoic acid and removal of the protecting phthalimido group affords the otherwise inaccessible azidoanilines (equation 134). Some representative examples of azides recently synthesized by these methods, are shown in Table 11. 

The synthesis of aryl azides in high yields and under mild conditions by the reaction of aromatic nitroso compounds with hydrazoic acid has been reported by Maffei and co-workers . Their results are summarized in Table 14. No intermediates have yet been isolated from this reaction, although Maffei suggested the intervention of a diazohydroxide. If the quantity of hydrazoic acid employed is less... 

Table 14. Synthesis of azides from aromatic nitroso compounds and hydrazoic acid...

Aliphatic amines are mainly converted to a-substituted products [99,100], whereby especially the a-methoxylation leads to valuable reagents for synthesis. The intermediate iminium salts can be directly trapped by silyl enol ethers to form Mannich bases [108]. If the a-position is blocked or steric conditions favor it, N,N coupling to hydrazo or azo compounds occurs (Table 5, numbers 17-19). 1,1-Disubstituted hydrazines are dimerized to tetrazenes in fair to excellent yields (Table 5, numbers 20-24). The intermediate diaze-nium ions can attack enolizable carbonyl compounds to form aza-Mannich bases [109]. Arylazonaphthols undergo anodic oxidation, producing radical cations. These couple to biphenylbisazo compounds (up to 34%) or can be trapped by anisidine to form azodiphe-nylamines (up to 74%) [110a]. 

We see from Table 13.1 that most uncharged acids have the acidic proton bonded to oxygen, a halogen, or sulfur. Occasionally an acid may have H bonded to N as in hydrazoic acid (H—N=N=N), or to C, as in hydrogen cyanide (H—C=N). In most molecules an H atom bonded to C, N, P, Si, or B is not acidic. When writing the molecular formula of a compound with acidic and nonacidic H atoms, the acidic H atoms are shown first (see Appendix II). 

It was to be expected that the hydrazo and azo linkages in TAHT and TAAT molecules would desensitize these compounds relative to cyanuric triazide. Reported values are summarized in Table 4.19 [147]. 

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