Benzoyl chloride, pyrolysis

In a typical Knof procedure, 3jS-hydroxyandrost-5-en-17-one acetate is epoxidized with perbenzoic acid (or m-chloroperbenzoic acid ) to a mixture of 5a,6a- and 5)5,6)5-epoxides (75) in 99 % yield. Subsequent oxidation with aqueous chromium trioxide in methyl ethyl ketone affords the 5a-hydroxy-6-ketone (76) in 89% yield. Baeyer-Villiger oxidation of the hydroxy ketone (76) with perbenzoic acid (or w-chloroperbenzoic acid ) gives keto acid (77) in 96% yield as a complex with benzoic acid. The benzoic acid can be removed by sublimation or, more conveniently, by treating the complex with benzoyl chloride and pyridine to give the easily isolated )5-lactone (70) in 40% yield. As described in section III-A, pyrolysis of j5-lactone (70) affords A -B-norsteroid (71). Knof used this reaction sequence to prepare 3)5-hydroxy-B-norandrost-5-en-17-one acetate, B-noran-... 

One of the routes to epimestix>l begins with acylation of estradiol with benzoyl chloride to give the dibenzoate 5. Pyrolysis of the ester leads to formation of the 16,17-olefin. Hydroxylation by means of osmiiim tetroxide affords the cis-diol 7 due to the intermediacy of the cyclic osmate ester (6a)-, attack... 

The first representative of this group, a /3-acylamino-a,/8-unsaturated ester, yielded 67 through pyrolysis in diphenyl ether205-207 [Eq. (53)]. A modification of this method used a Schiff s base instead of die TV-acyl derivative of a j8-amino-a,j8-unsaturated acid.208 Similarly, enamino esters react with benzoyl chloride to yield 6//-l,3-oxazines.209... 

Friedel-Crafts condensation of benzo[Z ]thieno[3,2-Z ]thiophene-2-carboxylic acid chloride with m- and / -xylene affords ketones, which undergo Elbs pyrolysis (420 °C, 15 min) to form pentacyclic derivative 230 (2000JA1082). Analogous products were prepared from benzo[Z ]thieno[3,2-Z ]thiophene and (di)methyl homologues of benzoyl chloride. 

A stepwise process, via hydrogen migration tautomers arriving at the same products, has been shown by density-functional theory to be responsible for the observed products of indole pyrolysis. 3-Phenyl-3-nitrosoindole, on activation with benzoyl chloride, has been found to react with indoles and indolizines (as nucleophiles) to afford products of 1,2-addition which can undergo a 1,3-nucleophilic migration in... 

Srinivasan et al. published a one-pot synthesis of 2-aryl benzimidazoles 52 (Scheme 20) by reaction of 1,2-phen-ylenediamines with benzoyl chlorides in the presence of [BMIM][BF4] in a molar ratio of 1 1 (reactant/IL). Earlier, benzimidazoles 52 were synthesized in a two-step procedure involving S5nthesis of a monoacylated product that on cyclodehydrationbyheatinginaqueous acids and pyrolysis attemperatures200-350 Caffords thedesired product [124]. Thus, the authors used IL with a belief that the hydrogen bond interaction between the most acid hydrogen (NH... 

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