Synthesis 2001(14): 2085-2090
DOI: 10.1055/s-2001-18056
PAPER
© Georg Thieme Verlag Stuttgart · New York

Application of Organolithium and Related Reagents in Synthesis; Part 26. [1] Synthetic Strategies Based on Directed ortho- Metalation: Synthesis of 4-Methyl-2H-phthalazin-1-ones

Jan Epsztajn*, Zbigniew Malinowski, Jacek Z. Brzezińki, Monika Karzatka
Department of Organic Chemistry, University of Łódź , Narutowicza 68, 90-136 Łódź, Poland
e-Mail: epsztajn@krysia.uni.lodz.pl;
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Publication History

Received 5 July 2001
Publication Date:
10 August 2004 (online)

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Abstract

The synthesis of 3-hydroxy-3-methylisoindolin-1-ones 10, masked ortho-acetylated derivatives of anilides, via metalation (BuLi) of the benzanilides 1 and subsequent reaction of the generated bis-lithiated anilides 2 with acetylating agents such as acetic anhydride or ethyl acetate were studied. The 3-hydroxy-3-methylisoindolin-1-ones 10 thus obtained are very sensitive towards dehydration process, which caused their conversion into enamides 11. Conversion of 3-hydroxy-3-methylisoindolin-1-ones 10 or enamides 11 into the corresponding 4-methyl-2H-phthalazin-1-ones 13 by treatment with hydrazine, as a way of regioselctive transformation of the benzoic acids, is also described.

1

Part 25. Bieniek, A.; Epsztajn, J.; Kowalska, J. A.; Malinowski, Z., Submitted

1

Part 25. Bieniek, A.; Epsztajn, J.; Kowalska, J. A.; Malinowski, Z., Submitted