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Concise Synthesis of [1,1′‐Biisoquinoline]‐4,4′‐diol via a Protecting Group Strategy and Its Application for Potential Liquid‐Crystalline Compounds
Author(s) -
Kapatsina Elisabeth,
Mateescu Markus,
Baro Angelika,
Frey Wolfgang,
Laschat Sabine
Publication year - 2009
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.200900085
Subject(s) - chemistry , yield (engineering) , bromide , ether , chloride , benzoyl chloride , medicinal chemistry , hydrochloride , group (periodic table) , alkyl , acetyl chloride , derivative (finance) , benzoates , organic chemistry , stereochemistry , catalysis , materials science , economics , financial economics , metallurgy
The [1,1′‐biisoquinoline]‐4,4′‐diol ( 4a ), which was obtained as hydrochloride 4a ⋅2 HCl in two steps starting from the methoxymethyl (MOM)‐protected 1‐chloroisoquinoline 8 ( Scheme 3 ), opens access to further O‐functionalized biisoquinoline derivatives. Compound 4a ⋅2 HCl was esterified with 4‐(hexadecyloxy)benzoyl chloride ( 5b ) to give the corresponding diester 3b ( Scheme 4 ), which could not be obtained by Ni‐mediated homocoupling of 6b ( Scheme 2 ). The ether derivative 2b was accessible in good yield by reaction of 4a ⋅2 HCl with the respective alkyl bromide 9 under the conditions of Williamson etherification ( Scheme 4 ). Slightly modified conditions were applied to the esterification of 4a ⋅2 HCl with galloyl chlorides 10a – h as well as etherification of 4a ⋅2 HCl with 6‐bromohexyl tris(alkyloxy)benzoates 11b , d – h and [(6‐bromohexyl)oxy]‐substituted pentakis(alkyloxy)triphenylenes 14a – c ( Scheme 5 ). Despite the bulky substituents, the respective target 1,1′‐biisoquinolines 12, 13 , and 15 were isolated in 14–86% yield ( Table ).