ChemInform Abstract: PHOTOOXYGENATIONS OF SYDNONES AND AZOMETHINE IMINES

Bhat, V. V.; Dixit, Vandana; UGARKER, B. G.; Trozzolo, A. M.; George, M. V.

doi:10.1002/chin.197951142

Cited by 2 publications

(2 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1977, 310, 495, 501. (13) As described for other l-isopropyl-l,2,3,4-tetrahydroisoquinolines, 9 shows a characteristic magnetic nonequivalence of the two isopropyl methyl groups in the NMR spectrum, either as the free base or as the hydrochloride: Kajtar, M.; Radies, L. Chem. Commun.…”

Section: Scheme IImentioning

confidence: 87%

Studies on the synthesis of the benzo[a]quinolizidin-2-one ring system. Preparation of a 1,1-dimethyl derivative

Bosch¹,

Domingo²,

Linares³

1983

J. Org. Chem.

View full text Add to dashboard Cite

The first Synthesis of a 1,l-dialkyl-substituted bem[a]quinolizidin-2-0ne is reported. Condensation of mescaline and ethyl 2-(chloroformyl)-2-methylpropionate followed by Bischler-Napieralski cyclodehydration and sodium cyanoborohydride reduction gave tetrahydroiioquinoline 20, which was converted into amido ester 21 by reaction with ethyl acrylate. Dieckmann cyclization of 21 gave the desired tricyclic system 22. Alternative synthetic routes based on the BischlepNapieralski cyclization of N-phenethyl-&hydroxy amide 5 or N-phenethylpiperidine-2,4dione ethylene ketal 15 failed. The reluctance of the tertiary phenethyl amides 11 and 15 to give cyclized products under Bischler-Napieralski conditions contrary to the behavior of the secondary phenethyl amides 5 and 18 is discussed.Although attention to the benzo[a]quinolizidin-2-one ring system2 was initially focused on ita application as an intermediate in the synthesis of emetine and other related ipecac alkaloid^,^ the Brossi findings& about the reserpine-like activity of some $alkyl derivatives suggested that members with other substitution in ring C might be worthy of study. In this context, a number of 1-, 3-, and 4-alkyl-substituted, as well as 4,4-dialkyl-substituted, benzo-[a]quinolizidin-2-ones have been prepared2" for synthetic or/and pharmacological purposes, but to our knowledge only one unsuccessful attempt to synthesize a 1,l-dimethyl derivative by an intramolecular Mannich-type cyclization of an appropriate 3,4-dihydroisoquinolinium salt has been made.s Hence, the synthesis of this system by other methods seemed of interest.In this paper we report the first synthesis of a 1,l-dimethylbenzo[a]quinolizidin-2-one system and the full details of our different synthetic approaches. As a synthetic goal we chose a derivative possessing three methoxy groups on the aromatic ring! because of its similarity to several 2-(3,4,5-trimethoxyphenyl)-4-piperidinones prepared by us in previous work.' Initially, we planned the synthesis by Bischler-Napieralskie cyclization of hydroxy amide 5, which was expected to be readily accessible through condensation of mescaline and lactone 4, as shown in Scheme I. This methodology [two ring closures in N-(arylethyl)-6-hydroxy amides] has been successfully applied to the synthesis of the benzo[a]quinolizidine ring system: but no reports have been made of its extension to the 2-oxo series.Lactone 4, the key compound in this route, was prepared as follows. Ethyl 2,2-dimethylacetoacetate was allowed to react with sodium and ethyl formate according to the procedure developed for the diethyl analoguelo to give the hydroxymethylene derivative 1 which, without further purification, was converted (44% overall yield) into the hydroxy ester 2 by hydrogenation over Raney nickel catalyst. Cyclization to lactone 3 was initially effected by heating it in the presence of p-toluenesulfonic acid in benzene solution. Under these conditions, the desired compound 3 was isolated in low yield (29%), the enone 6 being the main product (40%). However, whe...

show abstract

Section: Scheme IImentioning

confidence: 87%

Studies on the synthesis of the benzo[a]quinolizidin-2-one ring system. Preparation of a 1,1-dimethyl derivative

Bosch¹,

Domingo²,

Linares³

1983

J. Org. Chem.

View full text Add to dashboard Cite

show abstract

“…Electron loss from the 3-fold degenerate t2 orbital of CH4 can lead to C2", DM, and C3l) Jahn-Teller-type distortions.8,10'19 Second-order analysis of the nearly isotropic triplet of quintets ESR spectrum observed for CD2H2+ (Figure 1) yields g^= 2.0029 (4), MiS0(H)| = 121. 7 (3) G, and Mis0(D)| = 2.22 (6) G. Multiplication of the D hfs by the appropriate nuclear g factor ratio yields 14.6 (4) G on the H "scale". The quintets result from two equivalent deuteriums (7=1) and the triplet from two equivalent hydrogens.…”

mentioning

confidence: 99%

Reaction of sydnones with ozone as a method of deamination: on the mechanism of inhibition of monoamine oxidase by sydnones

White¹,

Egger²

1984

J. Am. Chem. Soc.

View full text Add to dashboard Cite

ChemInform Abstract: PHOTOOXYGENATIONS OF SYDNONES AND AZOMETHINE IMINES

Abstract: Bei der Photooxidation der Sydnone (I) entstehen über diskutierte Zwischenstufen wie u.a. (II) und (III) die Triazole (IV).

Cited by 2 publications

References 1 publication

Studies on the synthesis of the benzo[a]quinolizidin-2-one ring system. Preparation of a 1,1-dimethyl derivative

Studies on the synthesis of the benzo[a]quinolizidin-2-one ring system. Preparation of a 1,1-dimethyl derivative

Reaction of sydnones with ozone as a method of deamination: on the mechanism of inhibition of monoamine oxidase by sydnones

Contact Info

Product

Resources

About