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3-Bromofuran is a liquid having a boiling point similar to that of water (102.5-102.6 °C), but with density significantly higher (1.6606 g/cm3 at 20 °C)
Contents
Synthesis
3-Bromofuran was obtained in minor amounts in 1887 as a byproduct in a reaction of 3-bromofuroic acid with calcium hydroxide. About four decades later this compound was prepared deliberately and in higher yield. Recently, 3-bromofuran has been prepared from 3,4-dibromofuran via ortho-metallation with butyl lithium in good yield. An elegant synthesis of 3-bromofuran is due to Fechtel who prepared this compound via a Diels Alder-bromination-reverse Diels Alder sequence.
Applications
3-Bromofuran is a versatile chemical intermediate, in that it is a convenient starting material for 3-substituted furans, and as such, has found application in the syntheses of drug substances or candidate drugs in a number of therapeutic classes, including chemotherapy agents, HIV drugs, type 2 diabetes, osteoporosis and Alzheimer's disease. Thus, the total synthesis of (+)-cacospongionolide B, a sesterterpene with anti-inflammatory properties, has been accomplished employing 3-furylboronic acid derived from 3-bromofuran. 3-Bromofuran has also found application in the fragrance chemical arena. Thus, 3-bromofuran was reacted with 3,3-dimethylallyl bromide and lithium diisopropylamide in THF solution, followed by reaction at with methyl iodide and N-butyllithium in THF, yielding rosefuran, a constituent chemical of the odor of the rose, and an insect sex attractant. The total synthesis of (−)-neothiobinupharidine, a bioactive alkaloid isolated from Nuphar pumila (the small yellow pond-lily) was accomplished in eight steps employing two moles of 3-bromofuran. Similarly, Salvinorin A, the primary hallucinogenic diterpene compound in Salvia divinorum, a Mexican plant used by Mazatec shamans has been synthesized from 3-bromofuran in eleven steps.