Explosion azide

The unstable explosive azide may be stabilised by adsorption for reprographic... 

Potential hazards arising from slow formation of explosive azides from prolonged contact of halogenated solvents with metallic or other azides are outlined. 

Aliphatic azides (CAUTION A highly explosive azide may be formed when dichloromethane is used as the solvent)... 

Azides, Thermochemistry of Explosive Azides was discussed by P. Gray T.E. Waddington in PrRoySoc 235, 106-10(1956)... 

Study of the Explosive Characteristics of Lead Azide Prepared Commercially 2)Wm.H.Rinkenbach, USP 1,914, 530(1933) "Method of Producing Noncrystalline Explosive Azide 3)W.E.Garner A.S.Gomm, JCS 1931, 2123 34 (Thermal de-compn and deton of LA crysts) 4)F.D. 

Never add sodium or powerful bases to chlorinated solvents - an explosion may occur. Reaction of azide salts with dichloromethane results in the formation of explosive azides. 

In 2006, two groups independently reported the novel asymmetric synthesis of tamiflu (106). Corey et al. reported a short enantioselective pathway for the synthesis of 106 from 1,3-butadi-ene and acrylic acid shown in O Scheme 22 [ 111 ]. The key steps of the synthesis are (1) Diels-Alder reaction of 1,3-butadiene (146) and trifluoroethyl acrylate (147) in the presence of chiral ligand 148 developed in the laboratory [112], (2) the introduction of two amino groups in tamiflu (106) without using potentially hazardous and explosive azide reagents, and (3) a novel S nBr4 - catalyzed bromoacetamidation. 

Gray and Waddiiigion [103, 104] determined cxpciimciUally and calculated enthalpies for the formation of azides. A great difference exists between nonexplosive and explosive azides, as can be seen in Table 73. 

Potential hazards arising from slow formation of explosive azides from... 

A useful method for the separation ofhydrazoic acid is by a column extraction technique using a mixed-bed ion-exchange resin, a strongly acidic resin in the [H form], and a weakly basic resin in the (OH" form). All cations and most anions are held on the column while hydrazoic acid runs through the column. Other cations and anions elute as water. Weak acids, e.g., boric, silicic, and carbonic will also run through the column. The technique has not been applied to the analysis of explosive azides however, it has been used for the analysis of alkali azides and for the preparation of standard solutions of hydrazoic acid [18]. 

For instrumental analysis explosive azides must be converted to the chlorides or nitrates using semiconductor-grade acids. The sample is dissolved in semiconductor-grade nitric acid and ashed. The lead nitrate is then analyzed using flame, emission, X-ray, or mass spectroscopy neutron activation analysis or X-ray... 

An approach applicable to any scale of operation is to recognize not only direct hazards due to the explosivity of explosive azides, but also the indirect hazards resulting mainly from hydrolysis. Hydrolysis gives hydrazoic acid, HN3, a toxic substance which is physiologically very active and is also the medium by which very sensitive heavy-metal azides, most notably copper azide, can be formed. 

In addition to minimizing the amount, lead azide should not be stored Avith booster or main-charge explosives it should be kept in a separate magazine. Normally, any quantity of explosive azide greater than 10 g should be stored in 50% alcohol-50% water in order to minimize its sensitivity. It is sound practice to sample azides while they are wet and to dry only small portions as required. 

Care must also be exercised in the storage of azides to see that no material can react to form hydrazoic acid. In long-term storage of explosive azides in the presence of atomospheric or absorbed moisture, explosive azides may form on brass or copper heating pipes, radiators, refrigerator coils, etc., and for this reason compatibility of metals with HN3 must be kept in mind. 

The normal and preferred means for destroying an explosive azide is to explode it. In a laboratory where small quantities are used, it is strongly recommended that samples, as they outlive their usefulness, be exploded in small quantities in an appropriate laboratory area. Nonexplosive azides, of course, may be decomposed thermally, if they do not present any flame or flash hazard. However, for such materials, the preferred method is chemical destruction. 

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