Solid-phase synthesis of N , N ′-substituted acylguanidines

Chlorotrimethylsilane activation of acylcyanamides for the synthesis of mono-N-acylguanidines

A simple and efficient one-pot method for the synthesis of monoprotected guanidines is presented. Treatment of an acylcyanamide with chlorotrimethylsilane generates a reactive N-silylcarbodiimide capable of guanylating a variety of amines. Typically the reaction is complete in 15 min for primary and secondary aliphatic amines at rt. Hindered amines and anilines are also competent nucleophiles but require extended reaction times.

Efficient Synthesis of Polysubstituted Acylguanidines and Guanylureas

(Benzotriazol-1-yl)carboximidamides were applied for the preparation of polysubstituted acylguanidines and guanylureas. The reaction sequence utilized mild conditions and gave high yields for final compounds and intermediates. The protocol developed allows for variation of the substituents at all positions of the products.

A Traceless Approach for the Solid-Phase Synthesis of 6-Amino-1,3,5-triazine-2,4-diones

A traceless approach for the solid-phase synthesis of 6-amino-1,3,5-triazine-2,4-diones is described. Reaction of resin-bound S-methylisothiourea with isocyanates yielded resin-bound iminoureas 3, which reacted with amines to afford the corresponding guanidines 4. Following intramolecular cyclizative cleavage of the resin-bound guanidines using potassium ethoxide as a base, the desired products 5 were obtained in good yields and high purities.

New reagents, reactions, and peptidomimetics for drug design

It has been a major focus in our laboratories to prepare novel reagents and peptidomimetic structures for drug design. We have designed and prepared novel guanidinylation reagents that can be employed in solution or as solid phase reagents. We and others have utilized the reagent 3-(diethoxyphosphoryloxy)-1,2,3-benzotriazin-4(3H)-one (DEPBT) for amide bond formation to couple sterically hindered structures. These couplings proceed with remarkably strong resistance to racemization. In the area of peptidomimetics, we have incorporated novel building blocks to create biologically active compounds. These building blocks include thioether and alkylamine bridges, beta-methylated, and beta,beta-dimethylated amino acid residues. These mimetic structures have been incorporated into specific target molecules such as opioids to obtain cyclic peptidomimetics with potent and selective biological activity.