A study of the cyclodehydrohalogenation of 12-(2-chloro-5- methylphenyl)benz[a]anthracene

In the study of the cyclodehydrogenation of 12-(3-methylphenyl)benz[a]anthracene, Zajac pointed out that the hydrocarbon might undergo ring closure at either of the ortho positions of the phenyl ring. These positions are not equivalent with respect to the methyl group and ring closure might yield either 2-methyl dibenzo[a,l]pyrene or 4-methyldibenzo[a,l]- pyrene or a mixture of both isomers. When the compound, 12-(J-methylphenyl)benz[a]-anthracene, was dehydrogenated only one isomer was isolated. The isomer which was isolated could be either of the two possibilities. Therefore, it was decided to synthesize 2-methyldibenzo[a,l]pyrene unequivocally. By comparing the physical properties of the compound synthesized unequivocally with those of the compound from the cyclodehydrogenation of 12-(3-methylphenyl)benz[a]anthracene it can be determined which isomer was isolated by Zajac. Therefore, 12-{ 2-chloro-5-methylphenyl)benz[a]-anthracene was synthesized; this compound could then be cyclodehydrohalogenated to the corresponding 2-methyldibenzo[a,l]]pyrene. Using potassium hydroxide-quinoline and alkoxides led only to the recovery of starting material or to the destruction of it, depending on whether the reaction conditions were mild or drastic. Aluminum chloride destroyed the starting material in reaction time as short as five minutes. Stannic chloride destroyed only part of the starting material. An aluminum chloride-stannic chloride mixture also destroyed the starting material. In none of the experiments mentioned could the presence of 2-methyldibenzo[a,l]pyrene be detected. Although the right conditions for the cyclodehydrohalogenation were not found, the data obtained during the gas chromatographic studies are very valuable because it can be used for the other phases of the work being done in This Laboratory.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Chemistry

Department dc:contributor.department

Chemistry

Grantor dc:publisher

Virginia Polytechnic Institute

Year dc:date.issued

1963

Author dc:creator

• Yañez, José

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en_US

Handle dc:identifier.uri

http://hdl.handle.net/10919/74573

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/74573