Res. Chem. Intermed.
, Vol. 33, No. 6, pp. 535–540 (2007)
Also available online - www.brill.nl/rci
New process for the preparation of
, ZHIQIANG LIU
, YULUN XU
and SHUYING LIU
School of Chemical Engineering, Changchun University of Technology, Changchun,
Jilin 130012, P. R. China
Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Chanchun,
Jilin 130021, P. R. China
Received 30 August 2006; accepted 19 January 2007
Abstract—A new process for the preparation of 3,5-dihydroxy-1-pentylbenzene, which is used as
medicinal intermediate and raw material for the synthesis of HIV restrainer, is proposed in this
paper. Technical 3,5-dimethoxybenzoic acid reacted with lithium hydride to form a salt (I) which
acylated n-butyllithium directly to give 1-(3,5-dimethoxyphenyl)-1-pentanone (II) in 85.06% yield.
Then (II) was reduced through a Wolff-K-Huangminglong reaction at 210
C to give 3,5-dimethoxy-1-
pentylbenzene (III). Finally, (III) reﬂuxed with melt pyridine hydrochloride at 200
C for 2 h to afford
the target product 3,5-dihydroxy-1-pentylbenzene (IV). The total yield of (IV) amounted to 61.50%
and its mass percentage was 98.22%. The products were characterized by means of IR,
and HLPC-MS. The results indicated that this synthetic route was feasible, characterized by simple
process and higher yield, and superior to the published ones.
Keywords: HIV restrainer; 3,5-dihydroxy-1-pentylbenzene; 3,5-dimethoxybenzoic acid; acylation;
Wolff-K-Huangminglong reaction; demethylation.
3,5-dihydroxy-1-pentylbenzene (Olivetol) is an important medical intermediate.
Since its inhibition of human immune disease had been discovered in the 1980s,
it has gained wider application in this ﬁeld. Itself combined with other anti-
immune dysfunction drugs can lead to effective drugs to cure HIVs, tumors and
cancers . Moreover, Olivetol is also employed as the raw material to prepare
analgesics, pain-killing agents, sedatives and antihypertensive agents . Research
on its preparation has gained more and more attention. Korte et al.  proposed
To whom correspondence should be addressed. Tel.: (86-431) 571-6785;