4-azidobenzoyl chloride

Bis-PFPA 1 (18) was prepared from 4-azido-23,S,6-tetrafluorobenzoyl chloride and ethylene glycol. Bis-PFPA 2 (18) was obtained as a colorless solid from the reaction of dec uorobenzophenone and NaNj. Bisazide 3 (20) was thesized from 4-azidobenzoyl chloride (21) and ethylene glycol. Bisazide 4 (22) was prepared via diazotization of 4,4 -diaminobenzophenone followed ly treatment with sodium azide. 

Tosylates of pentaerythritol and the higher homologues can be converted to their corresponding tetra-, hexa-, or octaazides by direct reaction of sodium azide (36), and azidobenzoates of trimethyl olpropane and dipentaerythritol are prepared by reaction of azidobenzoyl chloride and the alcohols in pyridine medium (37). 

Smalley et al. reported the synthesis of the cyano-containing keto ester 98 by reaction of o-azidobenzoyl chloride 97 with cyanoacetic ester in the presence of triethylamine. This keto ester was then heated in acetonitrile for 30 min and gave the ring closed product 99 which was isolated in the fully aromatic tautomeric form 100 <1997S773>. A similar approach to tetrazolo[l,5- ]quinolines has been applied by a Korean research group in this case a reflux of the cyano-azido compound 101 for a longer period was needed in order to accomplish the cyclization to 4-acetoxymethyl-tetrazolo[l,5- ]quinoline 102 <2003JHC1103>. 

The pharmacologically important tryptanthrine, a quinazoline alkaloid, is known for its antimycotic activity and is used against skin infections. This alkaloid is obtained from isatin (260) and o-azidobenzoyl chloride (261), as shown in Scheme 96. The adduct formed is cyclized via a Staudinger and an aza-Wittig reaction to afford tryptanthrine (262) (92H153). 

Diazepines represent an important class of bicyclic seven-membered heterocycles. They are the basis of several tranquilizers and are accessible from a-amino acid esters and o-azidobenzoyl chloride in the presence of triethylamine. The A/ -(o-azidobenzoyl)amino esters (333) formed in this way (Scheme 121) are cyclized by Staudinger and aza-Wittig reactions to give 2-ethoxy-l,4-benzodiazepin-5-ones (334) (92MI2). 

Compounds of type 147 were directly acylated with the appropriate freshly prepared o-azidobenzoyl chloride 148. Following treatment of 149 with tributyiphosphine in toluene at room temperature afforded immobilised iminophosphoranes 150 that cyclised at 130°C presumably to the corresponding polymer-bound benzodiazepinediones 151. Acidolytic cleavage with 95% TFA in HjO and two lyophilisations from glacial acetic acid afforded crude 152 (Scheme 4.1.29). 

The reaction product of p-azidobenzoyl chloride with polyvinyl alcohol was investigated by Tsuda and coworkers [179]. In the polymer studied by them, over 90% of the hydroxy groups were esterified. The photocross-linking reaction was followed by observing changes in the ultraviolet and infra-red absorption spectra. It was shown that the simple photochemical reaction occurs stochiometrically upon... 

Thus, acylation of J -methylamides 38 with 2-azidobenzoyl chloride 37 (readily available from 2-azidobenzoic acid [142]) forms imides 39a-c, which upon treatment with triphenylphosphine (TPP) in the course of consecutive Staudinger reaction/intramolecular aza-Wittig reaction yield exclusively 3-methylquinazolin-4(3ff)-ones 40a-c quantitatively (Scheme 4) [143,144]. This procedure provides simple and efficient quinazoHnone annelation of amides and lactams. 

A 1.0-ml portion of thionyl chloride is added to the [ C]p-azido-benzoic acid in the 5-ml round-bottom flask containing a stirring bar. The solution is refluxed 0.5 hr and then cooled to room temperature. A micro distillation head is substituted for the condenser and the thionyl chloride is removed by distillation under reduced pressure (about 20 mm). A 0.5-ml portion of dry benzene is added and distilled this process is repeated twice to ensure thionyl chloride removal. The solid p-azidobenzoyl chloride is kept under reduced pressure until used ( 2 hr). 

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