Novel One-Pot Three- and Pseudo-Five-Component Reactions: Synthesis of Functionalized Benzo[g]- and Dihydropyrano[2,3-g]chromene Derivatives

Abstract

A novel and efficient method has been developed for the synthesis of highly functionalized benzo[g]- and dihydropyrano[2,3-g]chromene derivatives via addition and subsequently cyclization of 2-hydroxynaphthalene-1,4-dione or 2,5-dihydroxycyclohexa-2,5-diene-1,4-dione to the condensation product of an aldehyde with malononitrile in the presence of a catalytic amount of Et(3)N in CH(3)CN at ambient temperature. The procedures are very facile. The products can be obtained with simple filtration in high yields, and no more purification is needed. These compounds are closely related to ring systems such as beta-lapachone, alpha-xiloidone, lambertellin, pyranokunthone B, and WS-5995A, which have a broad spectrum of biological activities.

An improved procedure for the three‐component synthesis of benzo[g]chromene derivatives using basic ionic liquid

“…This compound was obtained as orange powder with mp 246−248°C (Lit. [11] 242−244°C); IR v max (KBr): 3411, 3325, 3188, 2204, 1669, 1634, 1595, 1514, 1407, 1362, 1242, 1201 cm −1 ; 1 H NMR (DMSO‐ d 6 ): δ 2.24 (3H, s, CH 3 ), 4.56 (1H, s, CH), 7.09−8.05 (10H, m, ArH and NH 2 ); 13 C NMR (DMSO‐ d 6 ): δ 20.5, 36.0, 57.5, 119.2, 122.1, 125.7, 126.0, 127.5, 129.0, 130.5, 131.0, 134.0, 134.5, 136.2, 140.6, 148.7, 158.2, 176.8, 182.5. Anal .…”

“…To the best of our knowledge, only few methods are available for the preparation of 4‐aryl‐5,10‐dihydro‐4 H ‐benzo[ g ]chromene‐5,10‐dione derivatives [11–14], however, these methods have various drawbacks: reactions require a long time, cannot be carried out one‐step operation, harsh reaction conditions, high temperature, and nonrecyclability. Therefore, it is desirable to develop a more efficient and a general method for the synthesis of 4 H ‐benzo[ g ]chromene derivatives.…”

An Efficient Synthesis of Tetracyclic Pyrano[2,3‐d]pyrimidines

“…All reagents purchased from commercial sources were used as received. 2‐Amino‐4‐aryl‐5,10‐dioxo‐5,10‐dihydro‐4 H ‐benzo[ g ]chromene‐3‐carbonitrile 1 , 2‐amino‐4‐aryl‐4 H ‐benzo[ h ]chromene‐3‐carbonitrile 2 , and 2‐amino‐5‐oxo‐4‐aryl‐4,5‐dihydropyrano[3,2‐ c ]chromene‐3‐carbonitrile 3 were prepared according to literature procedures . Melting points were determined with an X‐4 apparatus and were uncorrected.…”

Basic Magnetic Nanoparticles as Efficient Catalysts for the Preparation of Naphthopyrane Derivatives

“…The desired pure product(s) were characterised by comparison of their physical data with those of known compounds. [9][10][11][12][13][14][15][16][17][18][19][20][21][22] The spectral data of some representative naphthopyranes are as follows. …”