1.2.4- Triazoles 3-hydroxymethyl- from

Fifty ml fractions were collected. The product was eluted in fractions 20-44. The fractions were concentrated and the residue was crystallized from ethanol-ethyl acetate to give 1.64 g of melting point 138-142°C 0.316 g of melting point 138.5-141°C 0.431 g of melting point 139-141°C (72.8% yield) of 5-chloro-2-[3-(hydroxymethyl)-5-methyl-4H-l,2,4-triazol-4-yl]benzophenone. The analytical sample had a melting point of 138-139°C. 

Chloro-2-[3-(bromomethyl)-5-methyl-4H-l,2,4-triazol-4-yl]-benzophenone A solution of 5-chloro-2-[3-(hydroxymethyl)-5-methyl-4H-l,2,4-triazol-4-yl]-benzophenone (328 mg, 0.001 mol) in dry, hydrocarbon-stabilized chloroform (5 ml) was cooled in an ice-bath and treated with phosphorus tribromide (0.1 ml). The colorless solution was kept in the ice-bath for 55 minutes, at ambient temperature (22-24°C), for 5 hours. The resulting yellow solution was poured into a mixture of ice and dilute sodium bicarbonate. This mixture was extracted with chloroform. The extract was washed with brine, dried over anhydrous magnesium sulfate and concentrated. The residue was crystallized from methylene chloride-ethyl acetate to give 0.285 g of melting point 200-240°C (decomposition) and 0.030 g of melting point 200-220°C (decomposition) of 5-chloro-2-[3-(bromomethyl)-5-methyl-4H-l,2,4-triazol-4-yl]benzophenone. The analytical sample had a melting point of 200-240°C. 

A convenient synthesis, which leads toA-hydrogen-l,2,3-triazoles, utilises the stable (and relatively safe) trimethylsilyl azide. Alternatively, by conducting a cycloaddition in the presence of formaldehyde, A-hydroxymethyl-triazoles are formed (mainly the 2-isomer from isomerisation of initially formed 1-hydroxymethyl-triazole) from which AT-unsubstituted heterocycles can be easily obtained using base azidomethanol is formed in situ and is the entity that adds to the alkyne. ... 

Pale et al. developed the one-pot synthesis of 1,2,3-triazoles from alkylhalides, NaNj, and terminal alkynes mediated by a Cu(I)-modified zeolite (Scheme 4.15) (Beneteau et al., 2010). Also, Cn(I)-zeolites could smoothly promote the multicomponent synthesis of hydroxymethylated 1,2,3-trizoles from epoxides, NaN3, and terminal alkynes (Schane 4.16) (Boningari et al., 2010). However, a drawback of the method is that long reaction times are required. 

Disubstituted 1,2,3-triazoles are also formed from terminal alkynes and in situ-generated azides. For example, reactions of sodium azide, alkynes and aryl iodides in the presence of Cu(i) in a mixture of ionic liquids and water afford 1,4-disubstituted 1,2,3-triazoles Likewise, reaction of terminal alkynes with sodium azide and formaldehyde affords 2-hydroxymethyl-2/f-1,2,3-triazoles 20 (major isomer) in high yields... 

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