One-pot synthesis of 2-trifluoromethyl and 2-difluoromethyl substituted benzo-1,3-diazoles

Bromotriphenylphosphonium Salt Promoted Tandem One‐Pot Cyclization to Optically Active 2‐Aryl‐1,3‐oxazolines

“…[11] However, when non-fluorinated aryl acids were used to replace the fluorinated carboxylic acids, the formation of the corresponding aryl imidoyl chloride intermediates were not clearly detected, though the reactions still provided good formation of 1,3-oxazolines as final products. Instead, the formation of N-aroyl aziridines was distinctly observed, and they were separable as relatively stable intermediates in this tandem one-pot cyclization of aromatic acids with aliphatic β-amino alcohols.…”

“…[10] Our recent results revealed that the reaction of amino alcohols with carboxylic acids in the presence of a chlorotriphenylphosphonium salt in CCl 4 represents a direct and efficient approach towards aryl-fused oxazoles and oxazolines. [11] However, the overuse of CCl 4 in these experiments raised great environmental concern. Therefore, the development of a general, reliable, and environmentally friendly method for the synthesis of optically active 2-aryl-1,3-oxazolines is still highly desirable.…”

An expeditious one-pot solvent free synthesis of benzimidazole derivatives

“…It was followed by intra-molecular nucleophilic substitution by the remaining amine group in the orthoposition. 13 Aromatic aldehydes containing both electron-donating and electron-withdrawing groups worked well. Aliphatic aldehydes (Table 2, entry 9b) also afforded the desired products in high yields.…”

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“…An efficient and one-pot synthesis of 2-trifluoroand 2-difluoromethyl substituted benzothiazole derivatives in excellent yields by the condensation reaction of trifluoroacetic acid and difluoroacetic acid with commercially available 2-aminobenzenethiols, respectively, was examined by Ge and co-workers (Scheme 16) 36 .…”