1,4-Dimethylnaphthalene

1,4-dimethylnaphthalene is a growth inhibitor used on potatoes. It has a very low aqueous solubility and is highly volatile.

1,4-Dimethylnaphthalene is a polycyclic aromatic hydrocarbon (PAH) that has been found in dust particulate matter and is associated with activation of aryl hydrocarbon receptor as a major toxic mode of action in WB-F344 cell line. 1,4-Dimethylnaphthalene has been found to retard the development of epidermoid carcinomas in hamster buccal pouch. 1,4-Dimethylnaphthalene alters the genes associated with the maintenance of a G1/S phase block possibly through the induction of the cell cycle inhibitors KRP1 and KRP2 in potatoes.

The commercial production of 1,4-dimethylnaphthalene typically involves a multi-step chemical process. One industrial method begins with the cyclization of 5-phenyl-2-hexene in the presence of acid catalysts to form crude 1,4-dimethyl-1,2,3,4-tetrahydronaphthalene. This intermediate is then subjected to dehydrogenation to yield crude 1,4-dimethylnaphthalene, which is subsequently purified through distillation to remove isomeric impurities like 1,3-dimethylnaphthalene. An alternative synthesis route uses 1,4-dichloronaphthalene and a methyl Grignard reagent in the presence of a nickel-phosphine catalyst, followed by distillation and solvent recovery, achieving high conversion efficiency and selectivity. Extraction from potato skins is also possible and has been explored as a more natural alternative for use as a sprout suppressant in stored potatoes.

ChEBI: A dimethylnaphthalene carrying methyl groups at positions 1 and 4.

The Journal of Organic Chemistry, 46, p. 1251, 1981 DOI: 10.1021/jo00320a005

Inhibits potato sprouting by mimicking natural plant hormones

Plant Growth Regulator