Design and synthesis of new spiroheterocycles:Selective role of potassium fluoride in DMF

摘要

Potassium fluoride(KF)in dimethyl formamide(DMF)is found to be very effective and selective in the synthesis of spiro compounds.4-Bromo-4-carbethoxy-(4H)-1-phenyl-3-substituted-pyrazol-5-ones 4 are selectively converted to spiro derivatives by reacting with 5,8,11 and 16.