Stevens-type reaction

An efficient conversion of 5-chloro-)V-methylisatoic anhydride and glycine into 7-chloro-l-methyl-3,4-dihydro-lJT-l,4-benzodiazepine-2,5-dione has been described. Further reaction of its (V-acetyl derivative with phenylmagnesium chloride followed by treatment with hydroxylamine and then sodium bisulphite provides another new synthesis of Diazepam in ca. 50% overall yield. The 1,4,5-benzotriazocinium salts (103), prepared by the cyclization of (2-chloro-acetamido)benzophenone ATV-dimethylhydrazones (102), reacted with sodium methoxide in a Stevens-type reaction to give 3-amino-l,4-benzodiazepin-2-ones (104) in good yield. The same products were also obtained by direct treatment of (102) with base. 

The reaction of 1,3-dibromopropane with methyl methylsulfanylmethyl sulfoxide in the presence of base gave cyclobutanone via the intermediate formation of ftve-membered cyclic sulfonium salt 6, which was finally converted to 1-methylsulfinyl-l-methylsulfanylcyclobutane (7 a) by a Stevens-type rearrangement in 70% yield which on acid hydrolysis gave cyclo-butanone.142... 

The synthesis of 3-benzylcyclobutanone (3) is an illustration of an overall intramolecular alkylation of an acyl anion equivalent (Section 5.9). The a,a>-dihalide is 2-benzyl-l,3-dibromopropane, and the acyl anion equivalent is methyl methylthiomethyl sulphoxide2 the product is 1-methylsulphinyl-l-methylthio-3-benzylcyclobutane which is obtained as a mixture of cis/trans isomers [(9) and (10)] (Expt 7.3). Aqueous acid hydrolysis in ethereal solution unmasks the carbonyl group. The possible mechanism of the reaction is via a Stevens-type rearrangement of the intermediate sulphur ylide, which may proceed in a pericylic, radical or ion pair fashion. 

Reaction of benzyne with tertiary aliphatic amines to give anilines via Sommelet-Hauser and/or Stevens-type rearrangements of the intermediate ylid has been documented.362 363... 

Gill S, Hermolin RH. Case report of a Stevens-Johnson type reaction to celecoxib. Can J Hosp Pharm 2001 54 146. 

According to Huisgen [26] the reaction proceeds via ylide formation followed by a Stevens-type rearrangement. This was disputed by Franzen and Fikentscher [27] who found, using CH2, that EtOPr from EtOEt was labelled in the 7-position rather than the a-position expected from an ylide rearrangement. 

The intermolecular nature of the C1-C2 transformation step was shown by experiments using mono- C labelled dimethyl ether and analyzing the isotopic composition of the product ethylene. The intramolecular Stevens-type rearrangement under the reaction conditions was clearly ruled out. 

The reactions of sulphimides studied recently concern the kinetics of the reaction between PhSH and JV-toluene-p-sulphonyl-sulphimides - to give PhSSPh, or RSPh (other differences exist between the results from these two studies) the formation of vinyl sulphides by treatment of JV-toluene-p-sulphonyl aryl ethyl sulphimides with Bu OK [TsN=S(Et)Ar -> CHg= CHSAr] the halide-ion-induced Stevens-type rearrangement to the sulphen-amide [TsN=SRAr -> RN(Ts)SAr] and the S-substitution or Pummerer rearrangement products from iV-toluene-/j-sulphonyl-sulphimides by cleavage with NaOH or NaOMe in MeOH. °... 

The Bamford-Stevens decomposition of tosylhydrazones by base has been applied to steroids, although not extensively. It has been demonstrated that the reaction proceeds via a diazo compound which undergoes rapid decomposition. The course of this decomposition depends upon the conditions in proton-donating solvents the reaction has the characteristics of a process involving carbonium ions, and olefins are formed, often accompanied by Wagner-Meerwein-type rearrangement. In aprotic solvents the diazo compound appears to give carbene intermediates which form olefins and insertion products ... 

Phosphoryl-substituted diazo compounds of general type 4 have recently been synthesized by amine diazotization, Bamford-Stevens reaction, and diazo group... 

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