Azides, preparation from

The addition of the pseudohalogen iodine azide (prepared from iodine monochloride and sodium azide in acetonitrile) to methyl 5,6-dideoxy-2,3-di-0-p-tolylsulfonyl-a -L-arabtno-hex-5-enofuranoside has also been achieved a crystalline /3-iodo azide was isolated, in 69% yield, that was stable in the dark, but became colored on exposure to light.130 Brimacombe and coworkers133 have reported the addition of iodine azide to 5,6-dideoxy-l,2-0-isopropylidene-o -D-xy/o-hex-5-enofuranose X-ray crystallographic analysis established that the product is 6-azido-5,6-dideoxy-5-iodo-l,2-0-isopropylidene-/3-L-idofuranose. 

Diazo transfer. Tosyl azide is the most commonly used reagent for diazo Irnnsfcr, even though it is now recognized as a potentially dangerous explosive. Merck chemists have examined a number of other organic azides of these the safest is p-dodccylhciizcncsulfonyl azide, prepared from a commercial sulfonic acid mixture. 

Substituted 1,3-dithiol-2-yl-azides, prepared from the 1,3-dithiolium salts, give on thermolysis the... 

A general synthesis of c-fused pyridines under neutral conditions involves the thermolysis of vinyl azides, prepared from aromatic aldehydes that bear an ortho methyl group and ethyl azidoacetate. Thus thermolysis of the vinyl azide (151) from mesitaldehyde (150) gives the isoquinoline (152) in 45—50% yield (Scheme... 

Cu/Al203-catalyzed one-pot aryl azide preparation from aryl boronic acids and click" reaction. 

Table 5.4 Cu/Al203-Catalyzed One-Pot Aryl Azide Preparation from aryl boronic acids and Click Reaction ...

The resulting 2-benzylthioethylamine could be debenzylated by treatment with sodium in liquid ammonia. However, when 2-benzylthioethylamine was treated with carbobenzyloxy-P-alanine azide (prepared from carbobenzyloxy-P-alanylhydrazide by nitrosation), 2-benzylthio-7V-(carbobenzyloxy-P-alanyl)ethyl-amine formed. Reduction with sodium in liquid ammonia was sufficient to remove both the benzyl and carbobenzyloxy protecting groups and, as noted above, reaction with pantolactone yielded pantetheine. Phosphorylation to the mono- and diphosphates of pantetheine has been effected with the corresponding dibenzylphospho-nates (vide supra, ATP). 

Impact sensitivity significantly depends on many aspects. Let us look at some of these properties starting with crystal size of the material under test. Colloidal silver azide prepared from concentrated solutions exhibits significantly lower sensitivity (0.5 kg from 77.7 cm) than coarser crystals prepared from diluted solutions, which required less than half the energy (0.5 kg fi om 28.5 cm). MF measured under the same conditions for comparison required 12.7 cm with the 0.5 kg hammer [20]. It is interesting to note that the impact sensitivity of S A (in fine powdery form), which is considered very sensitive, is lower than that of MF. Similar investigations have... 

A novel method of synthesis of /8-glycosides (including disaccharides) of 2-acetamido-2-deoxy-D-glucose uses 2-deoxy-2-iodo-D-mannosyl azide (prepared from tri-O-acetyl-D-glucal) which gives access to the glycosides (via aziridine intermediates) on treatment with triphenylphosphine and alcohols in dichloromethane. In similar fashion, the D-gluco-iodoazide affords the 2-acetamido-2 -deoxy-a-D-mannopyranosides. 

Prepared from the 2- chloromethyl azide. ]] Prepared from the 2-dichloromethyl azide. 

M. Keshavarz, R. Badri, A fficile and one pot synthesis of l,4-disubstituted-lH-l,2,3-triazoles from terminal alkynes and phenacyl azides prepared from styrenes by CAN oxidant and sodium azide. Mol. Divers. 15 (2011) 957-962. 

Azides, Diazoalkanes, Azo- and Azoxy-compounds, and Azines. Tiifluoro methyl azide, prepared from trifluoronitrosomethane, was shown previously to react in a conventional manner with triphenylphosphine to yield a phosphine imine ... 

M.p. —80°C, b.p. 37°C. Prepared from sodium azide and acid or (N2Hj) plus nitrous acid, HNO2. Heavy-metal salts, azides, are used as detonators, alkali metal salts are stable and azides are used synthetically in organic chemistry. 

The Curtius rearrangement in acetic anhydride of the azide (8) prepared from 4-carboxythiazole yields 4-acetamidothiazole (Scheme 8) (47). The same reaction starting with ethyl-2-methyl-4-thiazolyl carboxy-late, failed to give the 4-aminothiazole (48). Heterocyclizations are more convenient synthetic methods (Chapter II. Table 40). 

Secondary amines having one oi two chiral groups attached to the nitrogen atom are prepared from boronic esters by their conversion into alkyldichlotobotanes, followed by treatment with organic azides (518). The second chiral group can be derived from an optically active azide. 

Pyrazolopyridines isomeric to those described previously have been obtained by other methods. Thus, the derivative (558) was formed by Raney nickel reduction of the 4-nitrosopyrazole (557) (7UHC1035), and the pyrazolo[3,4-c]pyridine derivative (560) was prepared from the azide (559) (79CC627). 

A third approach to 3-amino-/3-lactams is by Curtius rearrangement of the corresponding acyl azides. These are readily prepared from r-butyl carbazides, available via photochemical ring contraction of 3-diazopyrrolidine-2,4-diones in the presence of f-butyl carbazate (c/. Section 5.09.3.3.2). Thus treatment of (201) with trifluoroacetic acid followed by diazotiz-ation gives the acyl azide (202) which, in thermolysis in benzene and subsequent interception of the resulting isocyanate with r-butanol, yields the protected 3-amino-/3-lactam (203) (73JCS(P1)2907). 

This derivative, prepared from an amino acid and the acyl azide, is selectively cleaved in 80% yield by chymotrypsin. ... 

Putrescine dihydrochloride has been prepared by the Hofmann degradation of adipamide 3.. s by the Curtius degradation of adipyl hydrazide through the urethane by the Curtius degradation of adipyl azide obtained from adipyl chloride and sodium azide by the Schmidt degradation of adipic acid with hydrogen azide by the reduction of succinonitrile, succinaldoxime, or 7-phthalimidobutyronitrile with sodium and from N-ben-zoyl-7-iodobutylamine ... 

A solution of hydrazoic acid (prepared from about 30 g sodium azide) in ca. 200 ml chloroform is prepared in a well-ventilated hood. Cholesterol (15 g) is dissolved in the hydrazoic acid solution and 3.5 ml of triethylamine is added. The reaction mixture is then stirred at room temperature while 7 g of A-chlorosuccinimide is added. The reaction mixture is allowed to stand overnight and then the chloroform solution is washed successively with dilute sodium bisulfite, dilute soldium bicarbonate solutions and finally with water. The chloroform extract is then dried (Na2S04) and the solvent removed in vacuo. The residue is crystallized from ethanol to yield ca. 8.5 g of (101) in colorless needles mp 138-139°. The chloro azide is reduced to the aziridine by lithium aluminum hydride according to the foregoing procedure. 

The use of azide reagents is also important for the synthesis of cyclic sulfur(VI)-nitrogen systems. The reaction of SOCI2 with sodium azide in acetonitrile at -35°C provides a convenient preparation of the trimeric sulfanuric chloride [NS(0)C1]3 (Eq. 2.16). " Thionyl azide, SO(N3)2 is generated by the heterogeneous reaction of thionyl chloride vapour with silver azide (Eq. 2.17). This thermally unstable gas was characterized in situ by photoelectron spectroscopy. The phenyl derivative of the six-membered ring [NS(0)Ph]3 can be prepared from lithium azide and PhS(0)Cl. ... 

The free acid, l,2,3,4-thiatriazole-5-thiol, may be prepared from hydrogen azide and carbon disulfide, but the simplest way to obtain the acid is to treat a chilled solution of the sodium salt with concen-... 

Sodium azide does not react with carbonyl sulfide to form 5-hydroxy-1,2,3,4-thiatriazole, nor with carboxymethyl xanthates, RO-CS SCH2COOH, to form 5-alkoxy-l,2,3,4-thiatriazoles. The latter, however, could be prepared from xanthogenhydrazides (RO-CS NHNH2) and nitrous acid. They are very unstable and may decompose explosively at room temperature only the ethoxy compound (6) has been examined in detail. This is a solid which decomposes rapidly at room temperature and even at 0°C is transformed after some months into a mixture of sulfur and triethyl isocyanurate. In ethereal solution at 20° C the decomposition takes place according to Eq. (16)... 

A useful reaction sequence has been developed for conversion of an aromatic aldehyde into the next higher homologous acid. The nitro analog of 45, prepared from m-nitrobenzaldehyde, is converted into the azide 51 by hydrazinolysis and treatment with nitrous acid. The... 

The required acyl azide 1 can be prepared from the corresponding acyl chloride... 

Prepared from 40 g of sodium hydroxide, 20 g of potassium iodide and 0.5 g of sodium azide made up to 100 mL with water. 

The azide ion is a highly reactive polyatomic anion of nitrogen, N3 . Its most common salt, sodium azide, NaN3, is prepared from dinitrogen oxide and molten sodium amide ... 

Polymerization of a stable intermediate prepared from two monomers can produce an alternating copolymer. The amino acid azide hydrobromide method and the amino acid succinimidyl ester hydromide method were applied to prepare ordered copolyamides277) and sequential copolypeptides278-280). 

Tertiary alkyl azides can be prepared by stirring tertiary alkyl chlorides with NaN3 and ZnCl2 in 82 ° or by treating tertiary alcohols with NaN3 and CF3-COOH or with HN3 andTiCl4 or BF3. Acyl azides, which can be used in the Curtius reaction (18-14), can be similarly prepared from acyl halides, anhydrides, " esters, or other acyl derivatives. ° Acyl azides can also be prepared... 

Mg or Ca in MeOH, " baker s yeast, Sm/l2, LiMe2NBH3, and tin complexes prepared from SnCl2 or Sn(SR)2. This reaction, combined with RX —+ RN3 (10-65), is an important way of converting alkyl halides RX to primary amines RNH2 in some cases the two procedures have been combined into one laboratory step. Sulfonyl azides (RSO2N3) have been reduced to sulfonamides (RSO2NH2) by irradiation in isopropyl alcohol and with NaH. ... 

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