Process for the preparation of certain triaryl rhamnose carbamates

A process for preparing a substituted triazole of formula (II)

• wherein
• Y represents Cl, Br, I, OSO2CF3, OSO2CH3, or OSO2C6H4CH3, and
• Z represents a furanyl, phenyl, pyridazinyl, pyridyl, pyrimidinyl or thienyl group, unsubstituted or substituted with one or more substituents independently selected from F, Cl, C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 haloalkoxy or C1-C6 haloalkylthio,
• which comprises
• a) contacting a hydrazine hydrochloride of the formula
• Z—NH—NH2.HCl
• wherein
• Z represents a furanyl, phenyl, pyridazinyl, pyridyl, pyrimidinyl or thienyl group, unsubstituted or substituted with one or more substituents independently selected from F, Cl, C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 haloalkoxy or C1-C6 haloalkylthio,
• with urea in an aprotic organic solvent with a boiling point greater than 100° C. in the presence of a catalytic amount of an organic sulfonic acid at a temperature from about 100° C. to about 150° C.,
• b) further contacting the reaction mixture from step a) with a C1-C4 alkyl orthoformate and a catalytic amount of chlorosulfonic acid at a temperature from about 60° C. to about 100° C. to provide a substituted 1-H-1,2,4-triazol-3-ol of Formula (VIII)
• wherein Z is as previously defined, and
• c) converting the hydroxyl group of the triazole to a Cl, Br, I, OSO2CF3, OSO2CH3, or OSO2C6H4CH3.