Synthesis of 4-aryl-5,5-dimethyl-5H-1,2,3-triazoles and 4-aryl-3-cyano-5,5-dimethyl Δ1-pyrazolines by cycloaddition of 2-diazopropane with iminoethers and propenenitriles
摘要:
A regiospecific 1,3-dipolar cycloaddition of 2-diazopropane 3 to imimoethers 1a-c, carried out at 0 degrees C, afforded in two steps the corresponding 4-aryl-5,5-dimethyl-5H-1,2,3-triazoles 5a-c. Under the same conditions, 3-arylpropenenitriles 2a-d led to 3-cyano-5,5-dimethyl Delta(1)-pyrazolines 6a-d. Products 4-6 were obtained in good yields (69-85%). (c) 2006 Elsevier Ltd. All rights reserved.