Hydrazoic acid to give

It may be mentioned that bis(imino)thiazetidines (68), which are prepared by the reaction of carbodiimides with isothiocyanates, react with hydrazoic acid to give an aminothiatriazole. Although this reaction may be of interest from other points of view, it has no general synthetic application (equation 41) (81BSB63). 

R4 = R6 = H R3 = OH). A study of the Schmidt rearrangement of the diketone 136 (R = H, Me) showed that by choosing catalysts of different acidities either of the carbonyl groups can be made to react with hydrazoic acid to give all three isomeric benzazepines.166 Thus, sulfuric acid and sodium azide converted 136 (R = H, Me) into 137 (R = H, Me), while the use of hydrochloric acid afforded only the tetrazole 138 (R = H,... 

Miscellaneous Nitrogen Compounds.—In a novel synthesis of t-azido-compounds, 5a-pregnan-6j8-ol (457) reacted with BFa-hydrazoic acid to give a mixture of 5)8- (459) and 5a-azidopregnanes (460), in comparable proportions. The... 

Many functional groups besides the carbonyl group react with hydrazoic acid to give tetrazoles. In most of these reactions no catalyst is required. The tetrazoles thus obtained frequently are formed by rearrangement of intermediate azides. Since it may be desired to apply the Schmidt reaction to a molecule containing other functional groups or to a mixture of compounds, a few of the reactions leading to the formation of tetrazoles will be discussed briefly. 

Here HY is a proton donor and Z is a proton acceptor— in most cases these roles are performed by the amine and/or the solvent. All these reactions have a negative activation energy, and all the experimental observations can be accommodated by the mechanism shown in the Scheme. The same carbene complex, Cr(CO)s C(OMe)Ph, reacts with aminoethanol in two ways, to produce (14) and (15). Both are formed by attack at the carbene-C (14) arises from attack by HN=CHMe (aminoethanol minus the elements of water), and (15) from attack by NHg (aminoethanol minus the elements of acetaldehyde). The compound Cr(CO)6 acetoxy-(2-furyl)carbene reacts with hydrazoic acid to give Cr(CO)5(2-furonitrile). 

The reaction of carboxylic acids with hydrazoic acid in concentrated sulfuric acid to give amines is faster with acids whose t-factor equals 4. 

Olefins react with hydrazoic acid in sulfuric acid to give imines [51]. 

Tertiary alcohols or halides react with hydrazoic acid in sulfuric acid to give imines. Under the same conditions, benzhydrol gives A-benzylidene-aniline in 90 % yield [52]. 

Substituted salicylaldehydes react with hydrazoic acid in sulfuric acid to give indoxazenes 50,51 up to 15% of the corresponding 2-aminobenzoxazole (32) may be obtained as a by-product. The reaction is a variant of the Schmidt reaction, in which the intermediate nitre-nium ion may cyclize at once to the indoxazene, or rearrange and react with more hydrazoic acid, ultimately providing the benzoxazole. 

Earlier, Turrentine (Ref 4) obtained ferric azide in soln by electrolysis of a dil sodium azide soln using iron electrodes and later by Browne et al (Ref 6) on using iron electrodes in liq amm solns of ammonium azide, but the product was ammonolyzed to an Ammono-Basic Ferric Azide. Curtius et al (Refs 1 2), with ferric alum and NaN, obtained ferric azide in soln and they also repotted that iron dissolved in dil aq hydrazoic acid to form the azide, but the soln decompd on evapn giving either the basic azide or hydroxide. In 1934 Franklin (Ref 9) noted that aq hydrazoic acid reacts on iron to form ferric azide, nitrogen and ammonia together with a small amt of hydrazine. According to Franklin Ferrous Azide, Fe(Nj), is formed first and oxidizes to ferric azide when the soln is warmed with excess hydrazoic acid present. Ricca (Ref 11) studied the reactions of the ferric ion with hydrazoic acid on electrolysis of their solns and obtained results which would indicate that ferric azide has the structure [Fe(Nj)](Nj)2... 

In the Schmidt rearrangement, the treatment of a carboxylic acid with hydrogen azide (hydrazoic acid) also gives the amine, via the isocyanate, when catalysed by an acid, such as sulphuric acid. The first step is the same as the AAC1 mechanism to form the acylium cation, and so is favoured by hindered substrates. The protonated azide undergoes the rearrangement reaction. Illustrate this mechanism as well. 

Schmidt reaction. Acid catalyzed addition of hydrazoic acid to carboxylic acids, aldehydes, and ketones to give amines, nitriles, and amides, respectively. 

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