Phase transfer catalyzed acylation

Synthesis and Bioactivity of Pyrazole Acyl Thiourea Derivatives

“…The two different N-H protons appeared as two broad singlets at δ 9.07-9.58 ppm and δ 10.66-12.81 ppm respectively, whereas the pyrazole methyl protons showed up near δ 2.50 ppm as a singlet. The characteristic chemical shifts for F/CF 3 were also detected in the 19 F-NMR (CDCl 3 ) spectra of 6a-p.…”

“…The synthesized compounds were characterized by spectral data ( 1 H-NMR, 13 C-NMR, 19 F-NMR, IR) and elemental analysis. The compounds were subjected to in vitro fungicidal activity assays against G. zeae, F. oxysporum and C. mandshurica.…”

“…From Table 1 we can see that the reaction in the presence of phase transfer catalysis (PEG-400) has many advantages such as low reaction temperatures and high yields. The use of PTC make the heterogeneous system react smoothly, the yield of the product be improved obviously [18,19]. The reaction of 5 with suitably substituted fluorinated primary aromatic amines afforded the desired acyl thioureas 6a-p in good yields.…”

Synthesis, spectroscopic characterization, crystal structure and antifungal activity of thiourea derivatives containing a thiazole moiety

“…Target compounds were synthesized by a slight modification of our earlier published procedures [18][19][20]. The use of phase transfer catalysts to agitate a heterogeneous reaction system is gaining recognition [21,22]. In an attempt to improve syntheses of the target substituted thiourea derivatives by reacting isothiocyanates with nucleophiles, we have found the use of tetrabutyl ammonium bromide (TBAB) as phase transfer catalyst (PTC), it can improve the yield of aroyl, thiophenoyl, morpholinoyl and butanoyl based isothiocyanates.…”

Synthesis and herbicidal activity of N-(o-fluorophenoxyacetyl)thioureas derivatives and related fused heterocyclic compounds

“…[13][14] In search of improving methods to prepare the target acylthiourea by reacting acyl isothiocyanates with nucleophiles, we have found the use of TBAB as PTC can afford acyl isothiocyanates in good yield. In this paper, we have conducted our reaction using TBAB as phase transfer catalyst to synthesize the intermediate acylthioureas 5a-5e, then the compounds 5a-5e which undergo room temperature reaction with bromine to give the corresponding compounds 6.…”