Tributyltin azide

C2JH49N3OJS 80082-62-8) see Aztreonam 2-(tribUtylstannyl)vinyl ethyl ether (C H340Sn 20420-43-3) see Fluvastatin sodium tributyltin azide... 

J. Wiss and A. Zilian, Online spectroscopic investigations (FTIR/Raman) of industrial reactions synthesis of tributyltin azide and hydrogenation of chloronitrobenzene, Org. Process Res. Dev., 7, 1059-1066 (2003). 

The synthesis of valsartan (2) by Novartis/Ciba-Geigy chemists is highlighted in Scheme 9.5. Biphenylbenzyl bromide 18 is converted to biphenyl acetate 19 in the presence of sodium acetate in acetic acid. Hydrolysis of 19 followed by Swern oxidation delivered the biphenyl aldehyde 20, which underwent reductive amination with (L)-valine methyl ester (21) to give biphenyl amino acid 22. Acylation of 22 with penta-noyl chloride (23) afforded biphenyl nitrile 24, which is reacted with tributyltin azide to form the tetrazole followed by ester hydrolysis and acidihcation to provide valsartan (2). [See Biihlmayer et al. (1994, 1995).]... 

The short Sanofi route to irbesartan (3) is outlined in Scheme 9.6. Dihydroimidazolone 27, which is prepared from the reaction of 1-amino-cyclopentanecarboxylic acid ester (25) with ethyl pentanimidate (26) in the presence of acetic acid in refluxing xylene, is alkylated with biphenylbenzyl bromide 18 in the presence of sodium hydride in DMF to give 28. Finally, the synthesis of irbesartan (3) is completed by the tetrazole formation from reaction of the nitrile group of 28 with tributyltin azide in refluxing xylene. [See Bernhart et al. (1993a, b).]... 

The seemingly complex imidazolone (78-3) is in fact obtained in a single step by reaction of the amino-ester (78-1) with the iminoether (78-2) derived from capro-nitrile. The relatively acidic proton on the heterocyclic ring is next removed by reaction with sodium hydride. This anion is then alkylated with the same biphenyl-methyl bromide (77-2) that was used to prepare losartan to afford (78-4). The nitrile group is in this case converted to the tetrazole by means of tributyltin azide, a reagent that involves milder conditions than the traditional acidic medium used to generate hydrazoic acid. Thus, treatment of (78-4) with the tin reagent affords irbesartan (75-5) [82]. 

The presence of the propionamide fragment in the stmcture of the anti-inflammatory agent broperamole (125-1) is reminiscent of the heterocycle-based NSAID propionic acids. The activity of this agent may trace back to the acid that would result on hydrolysis of the amide. Tetrazoles are virtually always prepared by reaction of a nitrile with hydrazoic acid or, more commonly, sodium azide in the presence of acid in a reaction very analogous to a 1,3-dipolar cycloaddition. A more recent (and safer) version of the reaction noted later (see losartan, 77-4) uses tributyltin azide. In the case at hand, reaction of the anion of mefa-bromobenzonitrile (125-1) with sodium azide and an acid affords the tetrazole (125-2). Condensation of the anion from that intermediate with ethyl acrylate leads to the product from Michael addition saponiflcation gives the corresponding carboxylic acid (125-3). This is then converted to the acid chloride reaction with piperidine affords broperamole (125-4) [136]. 

Tributyltin azide reacts with carbon disulfide in solution to give what is supposed to be 4-(tributyltin)thiatriazoline-5-thione because, on evaporation of the solvent, tributyltin isothiocyanate is formed.42 However, isolation of this compound does not show whether tin is coordinated to S or N in the thiatriazole since rearrangements may have taken place. 

It was claimed that tetrazolyl derivative 455 was prepared from the appropriate nitrile on treatment with tributyltin azide in boiling o-xylene... 

Ethyl valerimidate Sodium cyanide Triethylamine Valeryl chloride Tributyltin azide... 

S)-N-(l-Carboxy-2-methyl-prop-l-yl)-N-pentanoyl-N-[2 -(lH-tetrazol-5-yl)biphenyl-4-ylmethyl]-amine. The product can be prepared starting from 1.40 g of N-valeryl-N-[(2 -cyanobiphenyl-4-yl)methyl]-(L)-valine methyl ester and 2.25 g of tributyltin azide with subsequent flash chromatography melting interval 105°-115°C (from ethyl acetate). 

The reaction of carbon disulfide with tributyltin azide and with [7r-C5H5Ni(PBu3)2]+N3-to give thiatriazoles or thiatriazolinethiones has been discussed (76AHC(20)l45,p. 165). 5-Mercaptothiatriazole complexes are believed to be formed by reaction of CS2 with azides of Rh, Pd, Pt, Co, Cu, Ag and Au. They may be thermally or photochemically converted into thiocyanato complexes (79JCS(D)37l). 

ATR-FTIR/Raman Synthesis of tributyltin azide and hydrogenation of l-chloro-2-nitrobenzene to 2-chloroaniline [14]... 

Like TMSA and DPPA, tributyltin azide is a covalently linked azide that allows for an azidation reaction in relatively homopolar solvents. In view of the high azide concentrations achievable in the solution, the use of TBSnA is interesting in terms of time (tetra-zole-yielding reactions are often slow on the basis of the two-phase reaction system NaN3 and nitriles) and thus for a technical realization (see also the examples in Sections 2.3.1.1 and 2.3.4). 

Table 2.4 Tributyltin azide (TBSnA) physical and chemical properties...

Tributyltin azide and acetylene dicarboxylic acid evolve hydrazine and form... 

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