1,5-Dibromopentane

clear colorless to yellow-brownish liquid and has an aromatic odor.. soluble in benzene and chloroform, insoluble in water.

1,5-Dibromopentane is used in the preparation of 1,5-di-Grignard reagent and novel spirocyclic pyrrolidones. It acts as a growth supplement for Yarrowia lipolytica 3589, a tropical marine yeast. It is involved in the synthesis of N-alkylated piperidine as well as tetrydrothiopyran (thiane) by reaction with primary amine and sodium sulfide respectively.

1,5-Dibromopentane can be used to prepare:
Derivatives of 5-pyrazolones.
O-alkylated phloroglucinol derivatives, which forms the core of poly(alkyl aryl ether) dendrimers.
Intermediate for dezocine viz, (R)-(+)-1-(5-bromopentyl)-1-methyl-7-methoxy-2-tetralone using 1-methyl-7-methoxy-2-tetralone.

1,5-Dibromopentane was obtained by ring-opening bromination of tetrahydropyran. In a 500ml flask, add 250g of 48% hydrobromic acid, 75g of concentrated sulfuric acid, 21.5g of redistilled tetrahydropyran (86.5-87.5°C fraction) in turn to a reflux condenser and heat the brown mixture gently to reflux for 3h. After cooling to room temperature, partition the lower layer of dibromide and wash each with saturated sodium carbonate solution and water once. Dried with anhydrous calcium chloride. Distill under reduced pressure and collect the 104-106°C (2.53 kPa) fraction as 1,5-dibromopentane in 46-47 g yield and 80-82% yield.

1,5-Dibromopentane synthesis route

Organic Syntheses, Coll. Vol. 3, p. 692, 1955
The Journal of Organic Chemistry, 48, p. 1678, 1983 DOI: 10.1021/jo00158a018

1,5-Dibromopentane is a growth supplement for Yarrowia lipolytica 3589, a tropical marine yeast.