A comparison of guanylating agents 1 and 2 was performed on a series o
f primary, secondary and aromatic amines in solution and on solid phas
e resins. Thiourea 1 performed well in solution and on solid supported
primary and secondary amines. Pyrazole 2 performed well in each case,
except one aniline which failed to react. (C) 1997 Published by Elsev
ier Science Ltd.