A. Baeyer; P. Fritsch (1884), "Ueber die o-Oxyphenylessigsäure und ihre Derivate", Chem. Ber., vol. 17, no. 1, pp. 973–975, doi:10.1002/cber.188401701258
T. Fukagawa; Y. Fujiwara; H. Taniguchi (1982), "Palladium-catalyzed intramolecular aromatic nuclear acyloxylation: preparation of 2-coumaranone", J. Org. Chem., vol. 47, no. 12, pp. 2491–2493, doi:10.1021/jo00133a055
R. Krieg; B. Hoffmann; D. Weiß; C. Biskup (2019), "First synthesis of highly chemiluminescent benzo[b]furan-2(3H)-ones bearing a urea substructure", Helv. Chim. Acta, 102 (6): e1800243, doi:10.1002/hlca.201800243, S2CID107893512
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EP 1481959, W. Jary, "Verfahren zur Herstellung von Lactonen und von aromatischen Hydroxycarbonsäuren", published 2004-12-01, assigned to DSM Fine Chemicals Austria Nfg GmbH & CO., KG
US 5616733, J.-C. Vallejos; A. Perrard & Y. Christidis et al., "Preparation method for 2-coumaranone", published 1997-4-1, assigned to Société Française Hoechst
EP 0818451, N. Carmona; L. Carmona & A. Perrard et al., "Procédé de préparation de l'énollactone de l'acide 2-oxocyclohexylidène acétique et application à la préparation de la 2-coumaranone", published 1998-01-14, assigned to Clariant Chimie S.A.
EP 149838, M. Stanek; P. Hildebrand & C. Zimmermann et al., "Verfahren zur Herstellung von 2-Coumaron und substituierten 2-Coumaronen", published 2004-08-25, assigned to DSM Fine Chemicals Austria Nfg GmbH & CO., KG
US 7070630, M.-I. Lim, Y.-G. Pan, "Primary intermediates für oxidative coloration of hair", published 2006-4-7, assigned to The Procter & Gamble Co.
EP 2508517, A. Shoutteeten, F. Bleger, F. Mordacq, J. Piron, "Process for the preparation of N-alkyl-2(hydroxy-4-benzoyl)-3-benzofurans and its intermediates thereof", published 2012-10-10, assigned to Clariant Specialty Fine Chemicals (France)
EP 2500341, C.-F. Chiu, C.-Y. Su, S. Lee, "Benzofuranone derivatives and application of the same", published 2013-06-26, assigned to Chitec Technology Co., Ltd., Double Bond Chemical Ind., Co., Ltd., FDC, Lees Chemical Industry Co. Ltd.
WO 199208703, J.D. Jones, G.A. DeBoos, P. Wilkinson, B.G. Cox, J.M. Fielden, "Process for the preparation of pyrimidine compounds", published 1992-5-29, assigned to Imperial Chemical Industries PLC
R. Krieg; B. Hoffmann; D. Weiß; C. Biskup (2019), "First synthesis of highly chemiluminescent benzo[b]furan-2(3H)-ones bearing a urea substructure", Helv. Chim. Acta, 102 (6): e1800243, doi:10.1002/hlca.201800243, S2CID107893512
