Abstract: A method for synthesizing 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide or its derivatives has a step of introducing 6-chloro-6H-dibenz[c,e][1,2]oxaphosphorin or its derivative, an acid compound and water into a reacting chamber to form an organic layer having 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide or its derivative and an aqueous layer. Because the acid compound is from an external source and has a catalyzing effect, employing the method can prevent side reaction from occurring and increase yield of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide or its derivative. Furthermore, the method is a one-pot operation of hydrolysis, dehydration and cyclization, so the method does not require purification of intermediates. Therefore, the method is time- and cost-saving and requires less organic solvent, resulting in less pollution to the environment.

Abstract: A method for synthesizing 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide or its derivatives has a step of introducing 6-chloro-6H-dibenz[c,e][1,2]oxaphosphorin or its derivative, an acid compound and water into a reacting chamber to form an organic layer having 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide or its derivative and an aqueous layer. Because the acid compound is from an external source and has a catalyzing effect, employing the method can prevent side reaction from occurring and increase yield of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide or its derivative. Furthermore, the method is a one-pot operation of hydrolysis, dehydration and cyclization, so the method does not require purification of intermediates. Therefore, the method is time-and cost-saving and requires less organic solvent, resulting in less pollution to the environment.

Abstract: A method for synthesizing benzotriazole comprises acts of: preparing a first solvent comprising 2-(2-hydroxy-5-methylphenyl) benzotriazole, a basic agent and molecular sieves and a second solvent comprising 3-chloro-2-alkyl propylene; mixing the solvents; and heating the solvents. This method requires only one reaction vessel and produces few by-products, therefore is simpler and cheaper to produce. Furthermore, the molecular sieves are cheaper than catalysts in conventional reactions and may be recycled, giving even greater economic benefits.

Abstract: A method for synthesizing benzotriazole comprises acts of: preparing a first solvent comprising 2-(2-hydroxy-5-methylphenyl) benzotriazole, a basic agent and molecular sieves and a second solvent comprising 3-chloro-2-alkyl propylene; mixing the solvents; and heating the solvents. This method requires only one reaction vessel and produces few by-products, therefore is simpler and cheaper to produce. Furthermore, the molecular sieves are cheaper than catalysts in conventional reactions and may be recycled, giving even greater economic benefits.