Reductive Heterocyclization of 2-Cyanobenzophenones by the Action of NaBH 4 . New Efficient Synthesis of 3-Arylphthalides

The reduction of 2-cyclopropylcarbonyl-, 2-(thiophen-2-yl)carbonyl-, and 2-arylcarbonylbenzonitriles with sodium tetrahydridoborate afforded 3-cyclopropyl-, 3-(2-thiophen-2-yl)-, and 3-arylphthalides, respectively, in high yields. Under analogous conditions, 3-cyanobenzophenones were converted to the corresponding 3-cyanobenzhydrols.