Recent Developments in the Use ofbis-(Trichloromethyl) Carbonate in Synthesis

Triphosgene and Triphenylphosphine Oxide-Mediated Cascade Heterocyclization of N-Acylated Anilines: One-Pot Synthesis of 2,4-Dichloroquinolines

A one-pot cascade chlorination/heterocyclization strategy has been developed for the synthesis of 2,4-dichloro-substituted quinolines from acylated anilines using triphosgene and triphenylphosphine oxide. Obviating the conventional harsh conditions of chlorination, synthetic useful quinolines with moderate to good yields were obtained through this reaction. The mechanism study exhibited that the formation of a β-enamine intermediate plays a vital role in the generation of the final product.

One-Pot Cascade Heterocyclization of γ- and β-Ketomalononitriles to 2,4-Dichloro-Substituted Pyrano[2,3- d]pyrimidines and Furo[2,3- d]pyrimidines Mediated by Triphosgene and Triphenylphosphine Oxide

A one-pot cascade heterocyclization strategy has been developed for the synthesis of 2,4-dichloro-substituted pyrano[2,3- d]pyrimidines and furo[2,3- d]pyrimidines from linear γ- and β-ketomalononitriles using triphosgene and triphenylphosphine oxide. The reaction afforded synthetic useful products with moderate to good yields, bypassing the conventional harsh conditions of chlorination. The mechanistic study revealed that the reaction proceeded with a non-isocyanate route, and the second step may conduct in a triphenylphosphine oxide-catalyzed manner.

Synthesis and Antitumour Activity of a Novel Class of Flavanones: 1,4-diaryl-1,4-dihydrochromeno[4,3-c]pyrazoles

A new series of 1,4-diaryl-1,4-dihydrochromeno[4,3- c]pyrazoles have been synthesised. The target compounds and their analogues (2,4-diaryl-2,4-dihydrochromeno[4,3- c]pyrazoles) were tested for their antitumour activities in vitro against MCF-7 and HL-60 cells using the MTT method. Among these compounds, 1,4-bis(4-chlorophenyl)-1,4-dihydrochromeno[4,3- c]pyrazole was found to have potent antitumour activity in vitro with minimum IC50 of 25.31 μg mL−1 and 13.86 μg mL−1 against MCF-7 and HL-60 cells respectively.

A New Approach to the Synthesis of 2,6-Dichloro-3-Fluorobenzonitrile: A Useful Pharmaceutical Intermediate

A highly efficient manufacturing-scale process for the preparation of 2,6-dichloro-3-fluorobenzonitrile, utilising industrial by-product 2,6-dichloro-3-fluoroacetophenone as starting material, has been developed. The overall yield was 77%.