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A series of naphthopyran derivatives 3a–f were prepared. Reaction of 2-amino-4-(p-chlorophenyl)-7-methoxy-4H-naphtho[2,1-b]pyran-3-carbonitrile (3b) with Ac2O afforded two products, 2-acetylamino-7-methoxy-4-(p-chlorophenyl)-4H-naphtho-[2,1-b]pyran-3-carbonitrile (4) and 10,11-dihydro-3-methoxy-9-methyl-12-(p-chloro-phenyl)-12H-naphtho[2,1-b]pyran[2,3-d]pyrimidine-11-one (5) and treatment of 3b with benzoyl chloride gave the pyranopyrimidin-11-one derivative 6. While treatment of 3b with formamide afforded 11-amino-3-methoxy-12-(p-chlorophenyl)-12H-naphtho[2,1-b]pyrano[2,3-d]pyrimidine (7). Reaction of 3b with triethyl orthoformate gave the corresponding 2-ethoxymethyleneamino-7-methoxy-4-(p-chlorophenyl)-4H-naphtho-[2,1-b]pyran-3-carbonitrile (8). Hydrazinolysis of 8 in EtOH at room temperature yielded 10-amino-10,11-dihydro-11-imino-3-methoxy-12-(p-chlorophenyl)-12H-naphtho[2,1-b]pyrano-[2,3-d]pyrimidine (9), while aminolysis of 8 with methylamine or dimethylamine gave the corresponding pyranopyrimidine and N,N-dimethylaminomethylene derivatives 10 and 11. Condensation of 9 with some carboxylic acid derivatives afforded triazolopyrimidine derivatives 12–16, while reaction of 9 with benzaldehyde gave 10-benzalamino-10,11-dihydro-11-imino-3-methoxy-12-(p-chlorophenyl)12H-naphtho[2,1-b]pyrano[2,3-d]pyrimidine (17). The structures of the newly synthesized compounds were confirmed by spectral data. The synthesized compounds were also screened for their antimicrobial activity.

Activities. -A variety of novel fused benzochromene derivatives are synthesized using readily available chromenecarbonitriles (IIId-f) as the key intermediates. The majority of the compounds synthesized show antimicrobial activity. -(KHAFAGY, M. M.; ABD EL-WAHAB, A. H. F.; EID, F. A.; EL-AGRODY*, A. M.; Farmaco 57 (2002) 9, 715-722; Dep. Chem., Fac. Sci., Al-Azhar Univ., Nasr City, Cairo 11884, Egypt; Eng.) -R. Langenstrassen 04-130

Condensation of 3-acetyl-8-ethoxycoumarin (3) with thiosemicarbazide gave ethylidenehydrazinecarbothioamide 5, which was transformed into the thiazolidin-4-one derivatives 6,7. Interaction of 3 with DMF/POCl3 gave β-chloroacroline derivative 8. Treatment of 3 with malononitrile gave benzo[c]chromone and 2-aminobenzonitrile derivatives 9 and 10, respectively with respect to the reaction conditions. Condensation of 3-(2-bromoacetyl)-8-ethoxycoumarin (4) with o-phenylenediamine gave 3-(quioxaline-2-yl)-8-ethoxycoumarin hydrobromide (11), while 4 reacted with 2-aminopyridine to give chromenopyridopyrimidine derivative 12. Condensation of 4 with potassium thio-cyanate/methanol gave an unexpected derivative, 2H-chromeno-3-carboxy(methyl-carbonimidic)thioanhydride 16, which upon treatment with (NH2)2·H2O gave 3-ethoxy-2-hydroxybenzaldehyde azine 19. Interaction of 4 with thiourea derivatives gave thiazole derivatives 20a–c. The structures of the newly synthesized compounds were confirmed by their spectra data. The newly synthesized compounds were also screened for their antimicrobial activity.

Preparation of 4-benzyl-2-substituted phthalazin-1-one derivatives 2-8 is reported. Condensation of 4-benzyl-1-chlorophthalazine (9) with a series of different nucleophiles gave 4-benzylphthalazin-1-ylamino derivatives (10-13 and 16) and 4-amino-2-[N′-(4-benzylphthalazin-1-yl)-hydrazino]-6-arylpyrimidine-5-carbonitriles (14a,b). Interaction of 9 with ambident anions was also studied. 5-Benzyl-6,6a,12-triazobenzo[a]-anthracen-7-one (15) is obtained from 9 and anthranilic acid derivatives. Treatment of 16 with (EtO)3CH/Ac2O under reflux afforded the corresponding ethoxymethylene derivative 17, while aqueous ammonium hydroxide treatment afforded carboxamide derivative 18. The structures of the newly synthesized derivatives were confirmed by their elemental analysis, IR, 1H NMR, 13C NMR and mass spectral studies. Antimicrobial activities of some selected compounds were also studied and some of these were found to exhibit promising effects against Gram-positive and Gram-negative bacteria and fungi.

SummaryA series of 6,8-diiodocoumarin-3-N-carboxamides (4–11) were prepared. Treatment of ethyl 6,8-diiodocoumarin-3-carboxylate (1) with ethyl cyanoacetate/NH4OAc gave ethyl 2-(3-carbamoyl-6,8-diiodocoumarin-4-yl)-2-cyanoacetate (12) and 2-amino-4-hydroxy-7,9-diiodocoumarino[3,4-c]pyridine-1-carbonitrile (13), and treatment with acetone in the presence of NH4OAc or methylamine gave the ethyl 4-oxo-2,6-methano-2-methyl-3,4,5,6-tetrahydro-8,10-diiodobenzo[2,1-g]-2H-1,3-oxazocine-5-carboxylate derivatives 14a,b. All compounds were evaluated for their antimicrobial activity and the compounds 12–14a,b exhibited a pronounced effect on all tested microorganisms.

KEYWORDSThis review deals with synthesis and reactions of some naphthopyrano derivatives and their applications. The main purpose of this review is to present a survey of literatures on the reactivity of naphthols and their derivatives toward α-cyanocinnamonitrile or ethyl α-cyanocinnamate derivatives and the reactions of β-enaminonitriles and β-enaminoesters with different electrophiles followed by nucleophilic reagents. Some of these reactions have been applied successfully to the synthesis of biologically important compounds. Naphthols Naphthopyran Nucleophilic reagents α-Cyanocinnamonitrile Naphthopyranopyrimidine Naphthopyranotriazolopyrimidine

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