THE SYNTHESIS OF SYRINGALDEHYDE FROM VANILLIN

1953 ◽  
Vol 31 (5) ◽  
pp. 476-483 ◽  
Author(s):  
J. M. Pepper ◽  
J. A. MacDonald
Keyword(s):  
Petroleum Ether ◽  
Paper Chromatography ◽  
Sodium Methoxide ◽  
Copper Catalyst ◽  
Anhydrous Methanol ◽  
Alkaline Solutions ◽  
Butyl Ether ◽  
Initial Separation ◽  
High Yields ◽  
Better Than

Syringaldehyde has been synthesized in high yields from vanillin. The process consists of the iodination of vanillin, followed by the interaction of the resultant 5-iodovanillin with sodium methoxide in anhydrous methanol at temperatures of 130 ± 4 °C. for one hour in the presence of a copper catalyst. Along with the syringaldehyde, small amounts of unchanged 5-iodovanillin and vanillin were always found in the reaction mixture. Analysis of the final product was made by an initial separation of the components by downward paper chromatography using a mixture of petroleum ether (b.p. 100–120 °C), di-n-butyl ether, and water (10: 1: 1) as the developing agent for a period of 10 hr. The separated compounds were extracted from the paper and their concentrations in alcoholic alkaline solutions determined spectrophotometrically.Under conditions by which 5-iodovanillin was converted to syringaldehyde in better than a 95% yield, 5-bromovanillin gave only a 61% yield and 5-chlorovanillin gave no detectable amounts of syringaldehyde.

AN IMPROVED SYNTHESIS OF ACETOSYRINGONE

1956 ◽  
Vol 34 (11) ◽  
pp. 1562-1566 ◽  
Author(s):  
L. W. Crawford ◽  
E. O. Eaton ◽  
J. M. Pepper
Keyword(s):  
Sodium Methoxide ◽  
Copper Catalyst ◽  
Subsequent Oxidation ◽  
Better Than

Acetosyringone has been synthesized from acetovanillone, in better than a 50% yield, through conversion to 5-iodoacetovanillone followed by its interaction with sodium methoxide in the presence of copper catalyst. The previously unreported intermediate, 5-iodoacetovanillone, was characterized by methylation to 5-iodoacetoveratrone and subsequent oxidation to the known 5-iodoveratric acid.

scholarly journals Synthesis and anticonvulsant activity of 6-methyl-2-((2-oxo-2-arylethyl)thio)pyrimidin-4(3 H)-one derivatives and products of their cyclization

Pharmacia ◽  
2019 ◽  
Vol 66 (3) ◽  
pp. 141-146
Author(s):  
Hanna Severina ◽  
Olga O. Skupa ◽  
Natalya I. Voloshchuk ◽  
Marharyta M. Suleiman ◽  
Victoriya A. Georgiyants
Keyword(s):  
Sulphuric Acid ◽  
Anticonvulsant Activity ◽  
Sodium Methoxide ◽  
Structure Activity ◽  
Phenacyl Bromides ◽  
Pharmacological Screening ◽  
High Yields ◽  
Derivatives Of

The alkylation of 6-methyl-2-thioxo-2,3-dihydro-1H-pyrimidine-4-one phenacyl bromides under different conditions was investigated. It was found that during the reaction in the medium of DMF/K2CO3 a mixture of 2-(2-aryl-2-oxoethyl)thio-6-methyl-pyrimidine-4(3H)-one and 3-hydroxy-3-aryl-7-methyl-2,3-dihydro-5H-thiazolo[3,2-a]pyrimidine-5-one was formed. The holding of the resulting mixture in the concentrated sulphuric acid leads to the formation of cyclization products - derivatives of 3-aryl-7-methyl-5H-thiazolo[3,2-a]pyrimidin-5-one with high yields. Individual S-alkylated derivatives – 2-(2-aryl-2-oxoethyl)thio-6-methyl-pyrimidine-4(3H)-one - were obtained by reacting in methanol in the presence of sodium methoxide. Pharmacological screening of synthesized compounds for anticonvulsant activity on the model of pentylenetetrazole seizures in rats was carried out and some regularity “structure-activity” was established.

scholarly journals One-Step Chromatographic Cleanup of Chlorinated Hydrocarbon Pesticide Residues in Butterfat. II. Chromatography on Florisil

1963 ◽  
Vol 46 (2) ◽  
pp. 172-176 ◽  
Author(s):  
William A Moats
Keyword(s):  
Petroleum Ether ◽  
Paper Chromatography ◽  
Pesticide Residues ◽  
Dairy Products ◽  
Methylene Chloride ◽  
Screening Procedure ◽  
Total Chloride ◽  
Chlorinated Hydrocarbon ◽  
Insecticide Residues ◽  
One Step

Abstract The procedure for chromatography on Florisil was modified by using methylene chloride-petroleum ether mixtures to improve separation of insecticides from fat. Combined with paper chromatography, it provides a screening procedure for insecticide residues in dairy products that is comparable in speed and simplicity to total chloride methods but is of superior sensitivity.

Five-membered ring annulation via thermal rearrangement of β-cyclopropyl α,β-unsaturated ketones. A formal total synthesis of the sesquiterpenoid (±)-zizaene

1982 ◽  
Vol 60 (23) ◽  
pp. 2965-2975 ◽  
Author(s):  
Edward Piers ◽  
Jacques Banville ◽  
Cheuk Kun Lau ◽  
Isao Nagakura
Keyword(s):  
Total Synthesis ◽  
Sodium Methoxide ◽  
Membered Ring ◽  
Yield Reduction ◽  
Thermal Rearrangement ◽  
Standard Methods ◽  
Unsaturated Ketones ◽  
Mild Conditions ◽  
Sodium Amalgam ◽  
High Yields

Treatment of the β-iodo enones 7–10 with lithium (phenylthio)(cyclopropyl)cuprate provided excellent yields of the corresponding β-cyclopropyl α,β-unsaturated ketones 11–14, respectively. When 3-isopropenyl-2-cyclohexen-1-one (16) was allowed to react with dimethyloxosulfonium methylide in dimethyl sulfoxide – tetrahydrofuran, 3-(1-methylcyclopropyl)-2-cyclohexen-1-one (17) was produced in 59% yield. Although thermal rearrangement (~425–450 °C) of compounds 11 and 17 produced high yields of the annulation products 19 and 22, respectively, similar reactions involving the β-cyclopropyl enones 12 and 13 were not efficient in terms of production of the corresponding bicyclic systems (23, 26, and/or 27, respectively). In these cases, predominant (24 + 25 from 12) or significant (28 + 29 from 13) amounts of monocyclic dienones were formed. The annulation product 22 served as a convenient starting material for a new formal total synthesis of the sesquiterpenoid (±)-zizaene (30). Conjugate addition of lithium divinylcuprate to 22 afforded the ketone 36 which was converted by standard methods (via 38 and 39) into the enone 40. Treatment of the latter substance with thiophenol in the presence of tetra-n-butylammonium fluoride gave 41, which was transformed via ketalization (41 → 42), hydroboration(42 → 43), tosylation (43 → 44), and oxidation (44 → 45) into the sulfone 45. When the latter compound was treated with potassium tert-butoxide in hexamethylphosphoramide, the tricyclic ketal sulfone 46 was produced in 85% yield. Reduction of 46 with sodium amalgam afforded the ketal 47, which upon hydrolysis under mild conditions gave the ketone 32. Treatment of the latter substance with sodium methoxide in methanol provided a 1:2 mixture of the epimeric ketones 31 and 32, which had been converted previously by Coates and Sowerby into (±)-zizaene (30).

scholarly journals Phytochemical Screening and Larvicidal Activities of Some Ethnobotanicals from North Eastern Nigeria against Culicine (Dipera: Culicidae) Mosquito

2019 ◽  
pp. 1-9
Author(s):  
R. S. Naphtali ◽  
J. S. Ngwamah
Keyword(s):  
Petroleum Ether ◽  
Phytochemical Analysis ◽  
Stem Leave ◽  
Methanol Extracts ◽  
Crude Extracts ◽  
Soxhlet Apparatus ◽  
North Eastern ◽  
Phytochemical Constituents ◽  
Larvicidal Activities ◽  
Better Than

This study was aimed to investigate the insecticidal activities of some selected ethnobotanicals against culicine mosquitoes. Various part of plant material collected were extracted using Soxhlet apparatus Methanol and Petroleum ether were used as solvents. Quantitative phytochemical Analysis for the crude extracts was carried out for the presence of azadrachtin, terpenoids, alkaloids, tannins, saponins, glycoside, steroids phenol and flavonoids. The larvicidal potentials of the various crude extracts were then tested against culicine mosquitoes. More yields of phytochemical constituents (80.78 mg) were found in total of 900 g used for methanol extracts as compared to 57.64 mg found in 900 g used in petroleum ether extracts. All the extracts of methanol and petroleum ether of the different plant used showed larvicidal potentials against culicine 3rd instar larvae. The LC50 of the methanol extracts (37.32, 38.52, 42.05, 45.91, 68.78, 126.56, and 141.73 ppm) of E. globulus, O. kilimanscharicum, H. suaveolens, Neem seeds, neem stem leave and orange peels respectively, are far better than their counterparts of petroleum ether extracts with LC50 (100.25, 115.53, 145.88, 68.44, 114.55, 46.79, and 175.07 ppm). The larvicidal effect of individual isolates of alkaloids, tannin, saponins, azadirachtin, phenol and steroids demonstrated larvicidal potentials against 3rd instar larvae of culicine, where, terpenoids, flavonoids and glycoside showed no larvicidal potentials against culicine larvae. The larvicidal potential of each plant depend on the number of active ingredients and quantity available in each extract. In conclusion, the present plant extracts have potentials for development of new and safe control products for culicine mosquitoes.

Copper-catalyzed asymmetric silyl addition to alkenyl-substituted N-heteroarenes

2020 ◽  
Vol 56 (11) ◽  
pp. 1693-1696 ◽  
Author(s):  
Ya-Li Zeng ◽  
Bo Chen ◽  
Ya-Ting Wang ◽  
Cheng-Yu He ◽  
Zi-Yuan Mu ◽  
...  
Keyword(s):  
Copper Catalyst ◽  
Conjugate Addition ◽  
Wide Range ◽  
High Yields

Asymmetric conjugate addition of PhMe2SiBPin to a wide range of N-heteroaryl alkenes proceeded in the presence of a copper catalyst coordinated with a chiral phosphoramidite ligand to afford useful β-silyl N-heteroarenes in high yields and ees.

Stereospezifischer Einbau von (—)5.7.4′-Trihydroxyflavanon in Flavonoide und Isoflavone

1966 ◽  
Vol 21 (3) ◽  
pp. 201-205 ◽  
Author(s):  
L. Patschke ◽  
W. Barz ◽  
H. Grisebach
Keyword(s):  
Cicer Arietinum ◽  
Paper Chromatography ◽  
Incorporation Rate ◽  
Biochanin A ◽  
Cicer Arietinum L ◽  
Better Than

(±)5,7,4′-Trihydroxyflavanone-5-glucoside-[2-14C] was synthesized and the diastereomeric (+) and (-) glucosides were separated by paper chromatography. In buckwheat seedlings the incorporation rate of the (-) enantiomer into quercetin was 16 times higher and into cyanidin 3.6 times higher than that of the (+) compound. In chana seedlings (Cicer arietinum L.) the (-) compound was incorporated into biochanin A (5,7-dihydroxy-4′-methoxy-isoflavone) 14 times better than the (+) compound, whereas in agreement with earlier results the incorporation of both enantiomers into formononetin (7-hydroxy-4′-methoxy-isoflavone) was very low.The results prove the stereospecific incorporation of the naturally occuring (-) · 2 · S · 5.7.4′-trihydroxyflavanone into flavonoids and isoflavonoids. The incorporation of the (+) enantiomer is probably due to a racemization of this compound via the chalcone.

Purification and Analysis of Bilirubin

1965 ◽  
Vol 11 (7) ◽  
pp. 681-690 ◽  
Author(s):  
John T Clarke
Keyword(s):  
Paper Chromatography ◽  
Extinction Coefficient ◽  
Gallbladder Bile ◽  
Alkaline Solutions ◽  
Human Calf

Abstract Pure crystalline bilirubin was isolated from human, calf, hog, and dog gallbladder bile and compared with commercially-available materials. All may be purified by recrystallization from pyridine. The extinction coefficient in chloroform is 60,000-61,000 at 450-453 mµ. Standardization of the analytical "azobilirubin" (van den Bergh) reaction may be based on aqueous alkaline solutions of bilirubin. Paper chromatography of azobilirubins derived from various sources of bilirubin showed identical patterns.

Finding potential high-yield areas for Mexican maize under current and climate change conditions

2015 ◽  
Vol 154 (5) ◽  
pp. 782-794 ◽  
Author(s):  
C. URETA ◽  
E. MARTÍNEZ-MEYER ◽  
E. J. GONZÁLEZ ◽  
E. R. ÁLVAREZ-BUYLLA
Keyword(s):  
Climate Change ◽  
Species Abundance ◽  
Null Model ◽  
High Yield ◽  
Centre Of Origin ◽  
Geographic Patterns ◽  
Methodological Approaches ◽  
High Yields ◽  
Mexican Maize ◽  
Better Than

SUMMARYAnalyses of the geographic patterns of wild species abundance have been carried out in studies ranging from those interested in hot-spots for biodiversity and conservation to basic ecological analyses. Based on the methodological approaches used, the present study searched for areas of higher yield among native races of maize in Mexico, its centre of origin and diversification. Ecological theory suggests that population fitness, and thus abundance, is maximal at the centroid of the multi-dimensional ecological niche of a particular species, and decreases progressively as distance from it increases. In the present study, yield was used instead of abundance, assuming it to be higher under optimal environmental conditions. It was assessed whether nine Mexican maize races exhibited higher yields in areas that are ecologically closer to their niche centroid (NC), or a niche optimum (NO) that did not always coincide with the geometric centroid. Environmental and geographical clusters for each race were also created to identify additional NOs in widely distributed races. All races showed significant correlations between yield and distance, both to the NC or NOs, but in only six of them was the chosen model better than the null model. Three races and two sub-groups were selected for projection under climate change conditions: Celaya (R2= 0·288), Celaya 3 (R2= 0·774), Vandeño (R2= 0·277) and Vandeño 2 (R2= 0·466) and Tepecintle (R2= 0·537). The Celaya race improved with environmental clustering, while Vandeño improved under geographical clustering. Finally, Tepecintle was projected at a race level. Projections under climate change suggested some potential areas for high yields in the future. It was concluded that the approach used in the present paper, considering the distance to NC/NO as a predictor of maize landrace yield, may contribute important information to agro-ecological projects.

scholarly journals 450 PB 291 CAROLINA BUNCH, A SWEETPOTATO FOR HOME GARDENS

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 495f-495
Author(s):  
J.R. Bohac ◽  
P.D. Dukes ◽  
A. Jones ◽  
J.M. Schalk ◽  
H.F. Harrison ◽  
...  
Keyword(s):  
South Carolina ◽  
Bright Light ◽  
High Yield ◽  
Southern Us ◽  
Dark Orange ◽  
Foundation Seed ◽  
Soil Insects ◽  
High Yields ◽  
Multiple Pathogen ◽  
Better Than

Carolina Bunch is a sweetpotato cultivar that combines high yield, excellent flavor and appearance with multiple pathogen and pest resistances. It is ideal for home or market gardens, because of its short vine and bunch habit that allow for production of high yields in a limited space. The roots are fusiform with uniform shape and a smooth, bright, light copper skin and dark orange flesh. When baked, the roots have a smooth texture and are sweet, moist and have excellent flavor and appearance. This sweetpotato can be grown virtually without pesticides. It has very high levels of resistances to southern root knot and other species of nematodes, Fusarium wilt, feathery mottle virus, sclerotial blight in plant beds, and Streptomyces soil rot. It has good resistance to many soil insects including several species of wireworm, Diabrotica, Systena, and flea beetles. In the southern US, it yields better than `Jewel' in a growing season of 110-120 days. Foundation roots are available in limited quantities from South Carolina Foundation Seed Association, Inc, 1162 Cherry Hill Rd, Clemson SC 29634-0393.

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