Reactions of 2-cyano-3-ethoxy-5,5-dimethyl-2-cyclohexen-1-one with 2-amino- and 2-hydrazionobenzimidazoles

The reactions of 2-cyano-3-ethoxy-5,5-dimethyl-2-cyclohexen-1-one with 2-amino- and 2-hydrazinobenzimidazoles gave 1-oxo-3,3-dimethyl-11-amino-1,2,3,4-tetrahydroquinazolino[3,2-a]benzimidazole and 2-(2-benzimidazolyl)-3-amino-4-oxo-6,6-dimethyl-4,5,6,7-tetrahydroindazole, respectively.Riga Technical University, Riga LV-1658. Latvian Institute of Organic Synthesis, Riga LV-1006. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 235–240, Feburary, 1997.     

Über das 4-Hydroxy-6,6-dimethyl-5,6-dihydro-2(1H)-pyridinthion bzw.-on und die entsprechenden Tautomeren

The tautomers, 4-hydroxy-5,6-dihydro-6,6-dimethyl-2(1H)-pyridinethione (1) and 6,6-dimethyl-2-thioxo-4-piperidone (2) resp., and 4-hydroxy-5,6-dihydro-6,6-dimethyl-2(1H)-pyridone (9) and 6,6-dimethyl-2,4-piperidinedione (10) resp. were synthesized by hydrolysis of 4-amino-5,6-dihydro-6,6-dimethyl-2(1H)-pyridinethiones (4, 5) and-ones (11, 12).1, 2 and9, 10 undergo an aminolysis in amines to the corresponding 4-aminodihydro-2(1H)-pyridinethiones4, 5 and-ones11, 12 resp.

     

Studies on substituted lactams. II

Synthesis and reactions of 4-carboxy-6-alkyl-2-piperidones and 4-carboxyl-6-alkyl-2-pyrrolidones are described. Upon heating, the substituted 4-carboxy-2-piperidones underwent both polymerization to polysuccinimides and isomerization to pyrrolidone derivatives. No polymerization but isomerization to ethylidene succinimide was observed upon heating the substituted 4-carboxy-2-pyrrolidone. Both polymerization and isomerization can be explained by mechanisms discussed previously.     

1- and 2-(4-Hydroxycarbonylphenyl)-4-oxo-4,5,6,7-tetrahydroindazoles

Reactions of 4-hydrazinobenzoic acid with 2-formyl- and 2-acetyldimedones were utilized to synthesize 6,6-dimethyl- and 3,6,6-trimethyl-1-(4-hydroxycarbonylphenyl)-4-oxo-4,5,6,7-tetrahydroindazoles corre-spondingly, and the reaction with 2-cyano-3-ethoxy-5,5-dimethylcyclohex-2-en-1-one gave 2-(4-hydroxy-carbonylphenyl)-3-amino-4-oxo-6,6-dimethyl-4,5,6,7-tetrahydroindazole. Riga Technical University, Riga LV-1658. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 516–519, April, 1997.     

Dioxo-2,5 pipérazines. 1. La synthèse des carboxythiazolo dioxo-2,5 pipérazines

A new and general synthesis of 2,5-dioxopiperazine condensed with the thiazolidine ring is described. The synthesis involves the use of N-ethoxy carbonyl-2-ethoxy-1-2-dihydroquinoleine (EEDQ) as activating agent to form the 2,5-diketopiperazine (EEDQ) as activating agent to form the 2,5-diketopiperazine ring. By this method 9-carbobutoxy-7,7-dimethyl-2,5-dioxo-8-this-1,4-diazabicyclo[4.3.0] nonane (6) and 9-carboxy-8,8 dimethyl-2,5-dioxo-7-thia-1,4-diazabicy clo [4.3.0] nonane (8) were obtained, with near quantitative yield, from 4-carboxy-2-carbobutoxy-5,5 dimethylthiazolidine (4). The former was transformed into acid 7 by hydrolysis with barium bydroxyde and the latter was esterified with diazornethane thus producing a methylester 9. The use of the ethy lester of N-(2-cabobutoxy-4-carboxy-5,5-dimethyl-thiazolidine)glycine (10) for synthesis of 6 was also successful. The spectromethric data were interpreted and confirm the proposed structure of the new compounds.     

1-(2-Quinoxalyl)-, 1-[3,5-Di(trifluoromethyl)phenyl]-, 1-(2-Carboxyphenyl)-, and 1-Ethoxycarbonyl-4-oxo-4,5,6,7-tetrahydroindazoles

The corresponding 1-(2-quinoxalyl)-, 1-[3,5-di(trifluoromethyl)phenyl]-, and 1-ethoxycarbonyl-3-methyl-4-oxo-4,5,6,7-tetrahydroindazoles have been obtained from reactions of 2-acetyl-1,3-cyclohexanedione, its 5,5-dimethyl and 5-(2-furyl) derivatives, with 2-hydrazinoquinoxaline, 3,5-di(trifluoromethyl)phenylhydrazine, and ethoxycarbonylhydrazine. On interaction with ethoxycarbonylhydrazine the intermediate 2-[1-(-ethoxycarbonyl)hydrazino]ethylidene-1,3-cyclohexanediones were also isolated. From the potassium salt of 2-formyldimedone and 2-carboxyphenylhydrazine hydrochloride, 2-(2-carboxyphenyl)hydrazinomethylene-5,5-dimethyl-1,3-cyclohexanedione was obtained, the cyclization of which in ethanol in the presence of HCl led to 1-(2-carboxyphenyl)- and 1-(2-ethoxycarbonylphenyl)-6,6-dimethyl-4-oxo-4,5,6,7-tetrahydroindazole.     

Synthesis,polymerization, and copolymerization of lactam-substituted styrenes

Four new substituted styrene derivatives carrying lactam rings (2-pyrrolidone or 2-piperidone) in para position have been synthesized, namely 4-(2-oxo-3-methylene-pyrrolidinyl)styrene, 4-(2-oxo-3-methylene-piperidinyl)styrene, 4-(p-styryl)-2-pyrrolidone, and 4-(p-styryl)-2-piperidone. Their homopolymerization and copolymerization with styrene, methyl methacrylate, and acrylic acid have been considered. By ring opening of the side lactam groups, the homopolymers are transformed into the corresponding poly aminocarboxylic acids.     

Five-membered dioxo heterocycles: CIV. Reaction of methyl 1-aryl-3-benzoyl-4,5-dioxo-4,5-dihydro-1H-pyrrole-2-carboxylates with cyclic enehydrazines. Crystal and molecular structure of N-[3′-benzoyl-1′-(4-chlorophenyl)-4′-hydroxy-6,6-dimethyl-2,4,5′-trioxo-1′,4,5,5′,6,7-hexahydrospiro-[indole-3,2′-pyrrol]-1(2H)-yl]benzamide

Methyl 1-aryl-3-benzoyl-4,5-dioxo-4,5-dihydro-1H-pyrrole-2-carboxylates reacted with N′-(5,5-dimethyl-3-oxocyclohex-1-en-1-yl)benzohydrazides and N′-(5,5-dimethyl-3-oxocyclohex-1-en-1-yl)-2,2-diphenylacetohydrazide to give substituted N-[1′-aryl-3′-benzoyl-4′-hydroxy-6,6-dimethyl-2,4,5′-trioxo-1′,4,5,5′,6,7-hexahydrospiro[indole-3,2′-pyrrol]-1(2H)-yl]benz- and -diphenylacetamides.     

Potassium fluoride-promoted reaction of (2-chloro-2-nitroethenyl)benzenes with 1,3-dicarbonyl compounds. A general synthesis of 6,6-dimethyl-2-nitro-3-phenyl-3,5,6,7-tetrahydro-4(2H)benzofuranones and some analogs

A convenient procedure to prepare in good yields 6,6-dimethyl-2-nitro-3-phenyl-3,5,6,7-tetrahydro-4(2H)-benzofuranones starting from (2-chloro-2-nitroethenyl)benzenes and 5,5-dimethyl-1,3-cyclohexanedione in the presence of potassium fluoride is reported. This method also proved efficient with other 1,3-dicarbonyl compounds, and has been successfully extended to 1,3-cyclohexanedione, 2,5-pentanedione, dibenzoylmethane and ethyl acetoacetate.     

Reaction of Acetone Cyanohydrin with Thiosemicarbazide

We have established that when acetone cyanohydrin is heated with thiosemicarbazide in aqueous medium, 3-mercapto-6,6-dimethyl-1,2,4-triazin-5-one and 2-methyl-2-thiosemicarbazidopropanoic acid are formed. Cyclization of the latter in dioxane in the presence of H₃BO₃ leads to 2-amino-5,5-dimethyl-1,3,4-thiadiazin-6-one.     

Synthesis of furo[2,3-c]pyran and some properties of 2-amino derivatives of furo- and pyrrolo[2,3-c]pyrans

Thesynthesisof2-amino-5,5-dimethyl-3-cyano-4,5-dihydro-7H-furo[2,3-c]pyrananditspyrroleanalog was accomplished on the basis of 2,2-dimethyltetrahydro-4-pyranone. Their reaction with maleic anhydride, which leads to the formation of 3-amino-4-cyano-6,6-dimethyl-5,6-dihydro-8H-pyrano[c]-phthalic anhydride, was studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 316–318, March, 1991.     

Benzacridines VI.. Functional derivatives of 5,6-dimethylbenz[c]acridine

5,5-Dimethyl-5,6-dihydrobenz[c]acridone has been synthesized by three different routes: a, from a condensation of anthranilic acid with 4,4-dimethyl-1-tetraIone; b, by a catalytic hydrogenation of 2-(o-nitrobenzal)-4,4-dimethyl-1-tetralone oxide followed by an acid catalyzed cleavage of the oxide ring and closure of the nitrogen heterocyclic ring; c, a multi-step process starting with 7-carboxy-5,5-dimethyl-5,6-dihydrobenz[c]acridine. Several new functional derivatives of both 5,5-dimethyl-5,6-dihydrobenz[c]acridine and of 5,6-dimethylbenz[c]acridine were also produced for biological study by others.     

4-Azaindane-1,3-dione derivatives

6,6-Dimethyl-2-methyl(or phenyl)-9-ethoxycarbonyl-5,6,7,8-tetrahydro-4-azabenz[f]indane-1, 3,8-triones were synthesized by reaction of 3-ethoxalyl-5-R-cyclopentaae-1,2,4-triones with 3-amino-5,5-dimethyl-2-cyclohexen-1-one. The products were alkylated, brominated, reduced, and hydrolyzed.     

Five-membered 2,3-dioxo heterocycles: LX. Reaction of 3-aroyl-1H-pyrrolo[2,1-c][1,4]benzoxazine-1,2,4-triones with cyclic enehydrazino ketones. Crystalline and molecular structure of N-[3′-benzoyl-4′-hydroxy-1′-(2-hydroxyphenyl)-6, 6-dimethyl-2,4,5′-trioxo-1′,4,5,5′,6,7-hexahydrospiro[indole-3,2′-pyrrol]-1(2H)-yl]-3-nitrobenzamide

3-Aroyl-1H-pyrrolo[2,1-c][1,4]benzoxazine-1,2,4-triones react with N′-(5,5-dimethyl-3-oxocyclohex-1-en-1-yl)benzohydrazides to give the corresponding N-[3′-aroyl-4′-hydroxy-1′-(2-hydroxyphenyl)-6,6-dimethyl-2,4,5′-trioxo-1′,4,5,5′,6,7-hexahydrospiro[indole-3,2′-pyrrol]-1(2H)-yl]benzamides. The molecular and crystalline structure of one of the products, N-[3′-benzoyl-4′-hydroxy-1′-(2-hydroxyphenyl)-6,6-dimethyl-2,4,5′-trioxo-1′,4,5,5′,6,7-hexahydrospiro[indole-3,2′-pyrrol]-1(2H)-yl]-3-nitrobenzamide, was determined by X-ray analysis.     

Synthesis of 5,6-Dimethylbenz[a]phenazine

5,6-Dimethylbenz[a]phenazine ( 4 ), an aza analogue of the carcinogenic 5,6-dimethylbenz-[c]acridine has been obtained by a 1,1-dehydration-rearrangement (Wagner-Meerwin type) from 5,5-dimethyl-6-hydroxy-5,6-dihydrobenz[a]phenazine ( 3 ). The alcohol 3 was obtained from the hydrogenation of the corresponding ketone 2 which was prepared in two ways: Method A, the oxidation of 5,5-dimethyl-5,6-dihydrobenz[a]phenazine ( 1 ); Method B, the hydrolysis of the 6,6-dibromo derivative 5 of 1.     

Synthesis and reactions of 1-(4-chloro-, 3-chloro-, 2-chloro-, 2,4-dichloro-, and 2,4-difluorophenyl)-6,6-dimethyl-4-oxo-4,5,6,7-tetrahydroindazoles

Reaction of the potassium salt of 2-formyldimedone with hydrochlorides of 4-chloro-, 3-chloro-, 2-chloro-, 2,4-dichloro-, and 2,4-difluorophenylhydrazines gave the corresponding 2-arylhydrazinomethylene-dimedones which cyclized in acid media to 1-substituted 6,6-dimethyl-4-oxo-4,5,6,7-tetrahydroindazoles. Oxidation of the latter with selenious acid gave the corresponding 4,5-dioxo-4,5,6,7-tetrahydroindazoles which were further converted into 3-aryl-5,5-dimethyl-4,5-dihydro-3H-pyrazolo[4,3-a]phenazines and 2,6-diaryl-4,4-dimethyl-4,5-dihydro-1H(3H)-indazolo[4,5-g]imidazoles.Riga Technical University, Riga LV-1658, Latvia; e-mail: marina@osi.lv. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, 533–539, April, 2000.     

Five-membered 2,3-dioxo heterocycles: XCI. Reaction of 3-aroyl-1H-pyrrolo[2,1-c][1,4]benzoxazine-1,2,4-triones with dimedone. Crystalline and molecular structure of 3′-benzoyl-4′-hydroxy-1′-(2-hydroxyphenyl)-6,6-dimethyl-6,7-dihydrospiro[1-benzofuran-3,2′-pyrrole]-2,4,5′(1′H,5H)-trione

3-Aroyl-1H-pyrrolo[2,1-c][1,4]benzoxazine-1,2,4-triones reacted with 5,5-dimethylcyclohexane-1,3-dione to give 3′-aroyl-4′-hydroxy-1′-(2-hydroxyphenyl)-6,6-dimethyl-6,7-dihydrospiro[1-benzofuran-3,2′-pyrrole]-2,4,5′(1′H,5H)-triones. The crystalline and molecular structures of 3′-benzoyl-4′-hydroxy-1′-(2-hydroxyphenyl)-6,6-dimethyl-6,7-dihydrospiro[1-benzofuran-3,2′-pyrrole]-2,4,5′(1′H,5H)-trione were determined by X-ray analysis.     

Synthesis of Enol Methyl Ethers of 3-Acetyl-6,6-dimethyltetrahydrothiopyran-2,4-dione and Their Reactions with Amines

The reaction of 3-acetyl-6,6-dimethyltetrahydrothiopyran-2,4-dione with diazomethane furnishes a mixture of 3-acetyl-6,6-dimethyl-4-methoxy-5,6-dihydro-2H-thiopyran-2-one and 3-acetyl-6,6-dimethyl- 2-methoxy-5,6-dihydro-2H-thiopyran-4-one in 2:3 ratio, whereas in reaction with dimethyl sulfate in the presence of potassium carbonate forms a mixture of the same products in 9:1 ratio. In both reactions the overall yield of ethers amounts to 50%. Treating of regioisomeric enol methyl ethers with pyrrolidine, o-toluidine, and allylamine provides the corresponding endocyclic enaminodiketones.     

A new biflavonoid from Selaginella labordei Hieron.ex Christ

A new biflavonoid,2,3-dihydro-5,5″,7,7″,4′-pentahydroxy-6,6″-dimethyl-[3′-O-4′″]-biflavone 1 and two known biflavonoids 2,3″-dihydroochnaflavone 2 and 2″,3″-dihydro-3′,3′″-biapigenin 3 were isolated from the herb of Selaginella labordei Hieron.ex Christ.Their structures were elucidated by spectroscopic methods.     

Five-membered 2.3-dioxo heterocycles: LXVIII. Three pathways in the reaction of methyl 3-aroyl-1-aryl-4,5-dioxo-4,5-dihydro-1H-pyrrole-2-carboxylates with 3-amino-5,5-dimethylcyclohex-2-en-1-one

Methyl 3-aroyl-1-aryl-4,5-dioxo-4,5-dihydro-1H-pyrrole-2-carboxylates reacted with 3-amino-5,5-dimethylcyclohex-2-en-1-one having no substituent on the nitrogen atom to give 3-aroyl-4-arylamino-6′,6′-dimethyl-6′,7′-dihydro-5H-spiro[furan-2,3′-indole]-2′,4′,5′(1′H,5′H)-triones or methyl 12-aroyl-11-aryl-9-hydroxy-5,5-dimethyl-3,10-dioxo-8,11-diazatricyclo[7.2.1.0^2,7]dodec-2(7)-ene-1-carboxylates. The latter underwent thermal recyclization to 3′-aroyl-1′-aryl-4′-hydroxy-6,6-dimethyl-6,7-dihydrospiro[indole-3,2′-pyrrole]-2,4,5′(1H,1′H,5H)-triones.