A Novel Approach for the Conversion of Primary Amides into Tetrazoles by Using Tributyltin Chloride and Sodium Azide in the Presence of DMF

Abstract

A novel and efficient one-pot synthesis of tetrazole -derivatives such as Irbesartan and its analogues has been described from the primary acid amide derivatives. Thus 2-alkyl-3-[ P-( O-amidophenyl)benzyl]-1,3-diazaspiro[4.4]non-1-en-4-one derivatives or 4-[α-(acylamino)cyclopentamidomethyl]-2′-carboxamidobi-phenyl derivatives were treated with tributyltin chloride and sodium azide in O-xylene in the presence of DMF to afford irbesartan and its analogues without generation of nitriles. The synthesis of these new starting materials is also described, and two of the derivatives have been used as new intermediates in the preparation of -irbesartan.