Fnedel-Crafts acylation

The key here is to recognize that an ethyl substituent can be introduced by Fnedel-Crafts acylation followed by a Clemmensen or Wolff-Kishner reduction step later in the syn thesis If the chlorine is introduced prior to reduction it will be directed meta to the acetyl group giving the correct substitution pattern... 

Fnedel-Crafts acylation of the individual isomers of xylene with acetyl chlonde and alu minum chloride yields a single product different for each xylene isomer in high yield in each case Write the structures of the products of acetylation of o m and p xylene... 

What combination of acyl chlonde or acid anhydnde and arene would you choose to pre pare each of the following compounds by Fnedel-Crafts acylation" ... 

Each of the compounds indicated undergoes an intramolecular Fnedel-Crafts acylation reac tion to yield a cyclic ketone Wnte the structure of the expected product in each case... 

Partial rate factors may be used to estimate product distributions in disubstituted benzene derivatives The reactivity of a particular position in o bromotoluene for example is given by the product of the partial rate factors for the corresponding position in toluene and bromobenzene On the basis of the partial rate factor data given here for Fnedel-Crafts acylation predict the major product of the reaction of o bromotoluene with acetyl chlonde and aluminum chloride... 

Fnedel-Crafts acylation In the presence of alumi num chloride acyl chlorides and carboxylic acid an hydrides acylate the aromatic ring of phenols... 

Acylation (Section 12 7 and Chapter 20) Reaction in which an acyl group becomes attached to some structural unit in a molecule Examples include the Fnedel-Crafts acylation and the conversion of amines to amides Acyl chloride (Sections 4 1 and 20 1) Compound of the type... 

The strong para-directing influence of fluorine in Fnedel-Crafts acylation is illustrated by the reaction of fluorotoluenes with acetyl chloride Treatment of 2-fluorotoluene, 3-fluorotoluene, and 2-fluoro-3-methyltoluene with acetyl chloride and aluminum chloride gives, respectively, 91, 82, and 80% substitution para to fluorine [27]... 

An alternative synthesis from the Glaxo patents involves Fnedel-Crafts acylation of the 3-position of the indole intermediate 22 (Scheme 5) Reaction of hydrazine 10 with (phenylthio)acetaldehyde gave hydrazone 20, which was subjected to the Fischer indole reaction to give 3-thiophenylindole 21. It is noteworthy that this Fischer cyclization took place at room temperature because most require heat. Reductive desulfurization of 21 using Raney nickel provided indole 22. Acylation of the 3-position... 

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