Benzoylation of 2(3H)-benzothiazolones in the Presence of 8 Equivalents of Zinc Chloride in N,N-dimethylformamide

FeCl3-DMF complex as efficient catalyst for the synthesis of 6-acyl-2(3H)-benzoxazolones and 6-acyl-2(3H)-benzothiazolones

“…The efficiency and applicability of these conditions were compared with reported methods commonly used for the preparation of 6-acyl-derivatives (Table 2) [24][25][26][27]29]. As Table 2 demonstrates, the behavior of 2(3H)-benzoxazolone and 2(3H)-benzothiazolone in the presence of FeCl 3 -DMF catalyst appears to be parallel to that in the case of AlCl 3 -DMF catalyst and in our method which afforded the best results [24][25][26][27][28][29]. We have exemplified the versality of our catalyst for different cases.…”

“…Due to their wide range of application, the syntheses of these derivatives by Friedel-Crafts acylation reaction have received great deal of attention [16][17][18][19][20][21][22][23]. In the literature, the most straight forward protocols using polyphosphoric acid (PPA), and Lewis acids such as aluminium chloride (AlCl 3 ) and zinc chloride (ZnCl 2 ) in N,N-dimethylformamide (DMF) as solvent, with carboxylic acids, acid chlorides or anhydrides have been reported [24][25][26][27][28][29].…”

“…Moreover, the Friedel-Crafts acylation using these conditions, generally involve the use of a large excess of catalysts and after aqueous work-up a large of amount of toxic waste is generated [24][25][26][27][28][29]. During recent years, the ferric chloride (FeCl 3 ) catalyst has been used as a catalyst in several organic transformations with excellent yields and great regioselectivity due to its low cost, ease of use, and environmental friendly properties [30][31][32][33][34][35][36][37][38].…”