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Synlett 2011(3): 383-385  
DOI: 10.1055/s-0030-1259507
LETTER
© Georg Thieme Verlag Stuttgart ˙ New York

Novel Palladium-Free Synthesis of a Key Quinazolinap Precursor

Ludovic Milhau, Patrick J. Guiry*
Centre for Synthesis and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland
Fax: +353(1)7162501; e-Mail: p.guiry@ucd.ie;
Further Information

Publication History

Received 13 December 2010
Publication Date:
25 January 2011 (online)

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Abstract

A novel, short synthetic route has been successfully developed for a key precursor of Quinazolinap ligands. The key step is a Friedel-Crafts-type reaction between 2-naphthol and 4-chloroquinazoline, with moderate to quantitative yields recorded. A variation of this reaction allows for the introduction of an amine group on the naphthalene unit.

Key words

arylation - Lewis acids - ligands - quinazolines - phenols

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Typical Procedure: 2-Naphthol (1 mmol), 4-chloroquinaz-oline (1 mmol) and AlCl3 (3 mmol) were suspended in DCE (3 mL) in a Schlenk tube under a nitrogen atmosphere. The mixture was heated at 80 ˚C for 3.5 h and then diluted with CH2Cl2 (15 mL). The mixture was washed with 1 M NaOH solution (15 mL), sat. NH4Cl solution (15 mL), H2O (15 mL), brine (15 mL), dried over MgSO4, filtered and eva-porated under reduced pressure. The crude product could be directly used in the subsequent steps of the synthesis without significant loss of yield compared to the use of pure compound. Nevertheless, purification was achievable by column chromatography using silica gel and CH2Cl2 as eluent. Compounds were identical to known samples.