Regioselective lithiation of chiral 3-acylamino-2-alkylquinazolin-4(3H)ones: application in synthesis

Smith, Keith, El-Hiti, Gamal A. and Abdel-Megeed, Mohamed F. 2004. Regioselective lithiation of chiral 3-acylamino-2-alkylquinazolin-4(3H)ones: application in synthesis. Synthesis (Stuttgart) (13) , pp. 2121-2130. 10.1055/s-2004-829169

Preview

Text - Accepted Post-Print Version Download (383kB) | Preview

Abstract

Reaction of 3-amino-2-alkylquinazolin-4(3H)-ones with several chiral acid chlorides was found to be dependent on the molar proportions. When a 1:1 molar mixture was heated under reflux, the corresponding 3-(diacylamino)- derivatives were obtained in poor yields. However, when a 2:1 molar mixture was reacted in refluxing toluene, the 3-acylamino- derivatives were obtained in good yields based on the acid chloride. Lithiation of the 3-acylamino-2-alkyl­quinazolin-4(3H)-ones was achieved by the use of lithium diisopropylamide (LDA) in anhydrous THF at -78 °C and the reaction was regioselective at the carbon α to position 2 of the quinazolin-4(3H)-one moiety. The dilithio reagents thus obtained reacted with electrophiles to give the corresponding 2-substituted derivatives in very good yields. The NMR spectra of the products show the expected diastereotopism for all the CH2 groups and provide evidence for long-range asymmetric induction.

Item Type:	Article
Status:	Published
Schools:	Chemistry
Subjects:	Q Science > QD Chemistry
Uncontrolled Keywords:	lithiation ; quinazolin-4(3H)-ones ; dilithio reagent ; asymmetric induction ; diastereotopism
Publisher:	Georg Thieme Verlag
ISSN:	0039-7881
Date of First Compliant Deposit:	30 March 2016
Last Modified:	05 May 2023 07:05
URI:	https://orca.cardiff.ac.uk/id/eprint/12708

Citation Data

Cited 32 times in Scopus. View in Scopus. Powered By Scopus® Data

Actions (repository staff only)

Edit Item