Annulation to the phthalazine ring system utilizing mesoionic ring systems

KT Potts, KG Bordeaux, WR Kuehnling…

Index: Potts, Kevin T.; Bordeaux, Kirk G.; Kuehnling, William R.; Salsbury, Ronald L. Journal of Organic Chemistry, 1985 , vol. 50, # 10 p. 1677 - 1681

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Citation Number: 14

Abstract

anhydro-3-Hydroxy-2-phenylthiazolo [2, 3-a] phthalizinium hydroxide, prepared from 1 (W)- phthalazinethione and a-bromophenylacetyl chloride or by Ac20/EtN ring closure of S-(1- phthalaziny1)-a-phenylthioglycolic acid, and dimethyl acetylenedicarboxylate in refluxing xylene (17 h) gave dimethyl 4-oxo-3-phenyl-4H-pyrido [2, 1-a] phthalazine-1, 2- dicarboxylate (85%). Fumaronitrile gave the corresponding 1, 2-dicyano product (93%), ...