This compound can be prepared by two related ways: 1) The condensation of 2-chloronicotinic acid (I) with 3-chloro-4-hydroxybenzonitrile (II) by means of sodium methoxide in nitrobenzene at 180 C gives 2-(2-chloro-4-cyanophenoxy)nicotinic acid (III), which by reaction with sodium azide in DMF at 100 C is converted into 2-[2-chloro-4(1H)-tetrazol-5-yl)phenoxy]nicotinic acid (IV). Finally, this compound is cyclized with H2SO4 at 180 C. 2) The cylization of gives 2-(2-chloro-4-cyanophenoxy)nicotinic acid (III) with H2SO4 at 180 C gives 9-chloro-5-oxo-5H-[1]benzopyrano[2,3]pyridine-4-carbonitrile (V) , which is then treated with sodium azide.

This compound can be prepared by two related ways: 1) The condensation of 2-chloronicotinic acid (I) with 3-chloro-4-hydroxybenzonitrile (II) by means of sodium methoxide in nitrobenzene at 180 C gives 2-(2-chloro-4-cyanophenoxy)nicotinic acid (III), which by reaction with sodium azide in DMF at 100 C is converted into 2-[2-chloro-4(1H)-tetrazol-5-yl)phenoxy]nicotinic acid (IV). Finally, this compound is cyclized with H2SO4 at 180 C. 2) The cylization of gives 2-(2-chloro-4-cyanophenoxy)nicotinic acid (III) with H2SO4 at 180 C gives 9-chloro-5-oxo-5H-[1]benzopyrano[2,3]pyridine-4-carbonitrile (V) , which is then treated with sodium azide.

This compound can be prepared by two related ways: 1) The condensation of 2-chloronicotinic acid (I) with 3-chloro-4-hydroxybenzonitrile (II) by means of sodium methoxide in nitrobenzene at 180 C gives 2-(2-chloro-4-cyanophenoxy)nicotinic acid (III), which by reaction with sodium azide in DMF at 100 C is converted into 2-[2-chloro-4(1H)-tetrazol-5-yl)phenoxy]nicotinic acid (IV). Finally, this compound is cyclized with H2SO4 at 180 C. 2) The cylization of gives 2-(2-chloro-4-cyanophenoxy)nicotinic acid (III) with H2SO4 at 180 C gives 9-chloro-5-oxo-5H-[1]benzopyrano[2,3]pyridine-4-carbonitrile (V) , which is then treated with sodium azide.