Anhydrous Potassium Carbonate Research Articles

A simple one-step synthesis of phenyl ethers from phenyl acetates

Phenyl acetates when refluxed with alkyl halides in acetone solution in the presence of a crown ether and anhydrous potassium carbonate undergo alkylation yielding phenyl ethers.

N2- and C-7 substituted actinomycin D analogues: synthesis, DNA-binding affinity, and biochemical and biological properties. Structure-activity relationship.

N2-n-Alkyl- and omega-amino-n-alkylactinomycin D and 7-alkoxy-, 7-aralkoxy-, and 7-(acyloxy)actinomycin D were synthesized by modification of the parent actinomycin D molecule at the N2 and C-7 positions of the phenoxazinone moiety. The intermediate for N2 substitution was 2-deamino-2-chloroactinomycin D. For C-7 substitution, 7-hydroxyactinomycin D was used as the intermediate. Treatment of 2-deamino-2-chloroactinomycin D with an excess of the appropriate amine produced the N2-substituted derivatives. Condensation of the required alkyl or acyl halides with 7-hydroxyactinomycin D, aided by solid anhydrous potassium carbonate, yielded the C-7-substituted analogues. Calf thymus DNA-binding affinity was determined by equilibrium binding and also by thermal denaturation of DNA techniques, inhibitory activity of nucleic acid synthesis was examined using P388 cells in vitro, cytotoxicity measurements to tumor cells in vitro employed human lymphoblastic leukemic cells (CCRF-CEM), and antitumor activity was assayed against P388 mouse leukemia in CDF1 mice. Synthesis of a number of new analogues in each series and determination of the biophysical, biochemical, and biological properties established a more thorough structure-activity relationship in these analogues. These results establish that with the selection of omega-(n-alkylamino) groups at the N2 site or O-n-alkyl or O-acyl groups at the C-7 site a variety of modifications can be carried out on the actinomycin molecule while preserving biological activity. N2-3'-Amino-n-propyl- and N2-10'-amino-n-decylactinomycin D, 7-methoxy- and 7-ethoxyactinomycin D, and the 7-O-(1'-adamantoyl) ester of 7-hydroxyactinomycin D were found to be the most effective antitumor agents in vivo and in vitro. They also strongly inhibit cellular RNA and DNA synthesis and, with the exception of the ester, retain high DNA-binding affinity.

Benzyl p-Toluenesulphonate as an 0-Benzylating Agent for the Protection of Phenols

Abstract Benzylation is a popular method of protecting phenolic groups during synthetic procedures. Benzyl ethers are stable to basic and mildly acidic conditions, but are cleaved readily by stronger acid, reduction, or most commonly by hydrogenolysis1. Current methods of converting phenols into O-benzyl derivatives rely principally on the use of commercially available benzyl chloride or benzyl bromide and usually involve heating a mixture of the phenol and the halide with anhydrous potassium carbonate in dry acetone or DMF1. To increase reactivity of the halide, potassium iodide may be added to the reaction mixture to generate benzyl iodide ‘in situ’. A major disadvantage of using alkyl halides in the preparation of phenolic ethers is the amount of simultaneous C-alkylation which can occur. Whilst C-alkylation is reduced by using polar aprotic solvents1, it may still become an important side reaction during the alkylation of phenols containing phloroglucinol substitution patterns, yields of 0-alkyl deriv...

Esterification of sterically hindered pyrrole carboxylic acids using dimethyl and diethyl sulfate under mild basic conditions

AbstractA simple and efficient method for the esterification of sterically hindered pyrrole carboxylic acids using dialkylsulfate and anhydrous potassium carbonate is described.

Heterocyclic steroids—Part VIII: Studies on the total synthesis of racemic 2-phenyl-7-methyl-3-oxa-A-nor-14β-estra-1,5 (10),6,8-tetraen-17α-ol

2-Phenyl-6-methyl-4-oxo-4,5,6,7-tetrahydrobenz ofuran (II) is converted into racemic 2-phenyl-7-methyl-3-oxa-A-nor-14β-estra-1,5(10),6,8-tetraen-17α-ol (VIII). Recent publications on A-ring heteroaromatic steroids and the total synthesis of heterocyclic steroids (l to 5) indicated that there has been no report on the total synthesis of A-nor-2-phenyl-5-oxaequilenin. It is also relevant to state here that steroids methylated in the 6β (6,7) and 7α (8) positions have been known to furnish biologically interesting products. Encouraged by these findings, we wish to report here the total synthesis of the title compound (VIII) (9). The required bicyclic ketone (II) was prepared in two steps starting with 5-methylcyclohexane-1,3-dione (10). 5-Methylcyclohexane-l,5-dione on treatment with phenacyl bromide in the presence of anhydrous potassium carbonate and dry chloroform at. room temperature afforded 2-phenacyl-5-methylcyclohexane-1,3-dione (I). Cyclodehydration of (I) with concentrated sulphuric acid at 0°

ChemInform Abstract: THYMIDYLATE SYNTHETASE INHIBITORS. SYNTHESIS OF N‐SUBSTITUTED 5‐AMINOMETHYL‐2′‐DEOXYURIDINE 5′‐PHOSPHATES

AbstractAus dem geschützten Chlormethyl‐uracil (I) werden die Substitutionsprodukte (IIa)‐(IId) hergestellt und nach Abspaltung der Toluoyl‐Schutzgruppen über (III) zu (IV) phosphoryliert.

Thymidylate synthetase inhibitors. Synthesis of N-substituted 5-aminomethyl-2'-deoxyuridine 5'-phosphates

A series of substituted 5-aminomethyl-2'-deoxyuridines was synthesized as analogues of 5-thymidylyltetrahydrofolic acid, a proposed intermediate in the thymidylate synthetase catalyzed reaction. 1-(3,5-Di-O-p-toluoyl-2-deoxy-beta-D-ribofuranosyl)-5-chloromethyluracil (3) was treated with the appropriate amine to give the ester protected 5-aminomethyl nucleoside. Removal of the ester groups was accomplished with anhydrous potassium carbonate in methanol to afford the free beta-nucleoside. In this way 5-(2-dimethylaminoethylaminomethyl)-2'-deoxyuridine (5a), 5-dimethylaminomethyl-2'-deoxyuridine (5b), 5-N-mehtylpiperazinylmethyl-2'-deoxyuridine (5c), and 5-pyrrolidinylmethyl-2'-deoxyuridine (5d) were prepared. Compounds 5a,b,d were converted to the respective 5'-phosphates 6a,b,d. All three compounds were subtrate competitive inhibitors of thymidylate synthetase purified from Escherichia coli, calf thymus, and Ehrlich ascites tumor cells. The most active compound was 6a with KI's of 6,3.1, and 14 micronM observed for the respective enzymes.

Synthetic application of cyclobutanes V. α-Carbalkoxymethylation of α, β-unsaturated ketones

Two general methods for α-carbalkoxymethylation of both enolizable and nonenolizable (towards the γ-position) α,β-unsaturated ketones have been developed. Method A involves three synthetic steps: photocycloaddition of the starting enone to 1,1-dimethoxyethylene, hydrolysis–oxidation of the adduct with acetic acid and 30% hydrogen peroxide, and O-alkylation of the resulting mixture of lactone and acid using anhydrous potassium carbonate and an alkyl iodide, e.g., 13 → 17 → 21 + 22 → 23. Method B differs from method A in the means of securing the required cyclobutanone intermediate. Thus, photocycloaddition of 13 to vinyl acetate followed by hydrolysis of the adduct gave two epimeric keto alcohols 39 whose oxidation with dimethyl sulfoxide and acetic anhydride afforded diketone 40. Baeyer–Villiger oxidation of 40 followed by methylation of the products 21 and 22 completed the overall α-carbomethoxymethylation process to give keto ester 23.

1-hydroxy-2-tert-butyldimethylsilyl-sn-glycero-3-phosphorylcholine. A useful intermediate in the synthesis of short acyl chain 1-acyl-sn-glycero-3-phosphorylcholines

The synthesis of 1-acyl-sn-glycero-3-phosphorylcholines in particular those containing short fatty acyl chains are described. The method involves the use of 1-acyl-2-tert-butyldimethylsilyl-sn-glycero-3-phosphorylcholines which can be readily prepared by reacting hens' egg yolk 1-acyl-sn-glycero-3-phosphorylcholines with tert-butyldimethylchlorosilane with imidazole as catalyst and dimethylformamide as solvent. Deacylation of the 1-acyl-2-tert-butyldimethylsilyl-sn-glycero-3-phosphorylcholines with saturated anhydrous potassium carbonate in methanol yields the 2-tert-butyldimethylsilyl-sn-glycero-3-phosphorylcholine. Reacylation of the 2-tert-butyldimethylsilyl-sn-glycero-3-phosphorylcholine with fatty acyl anhydride in the presence of 4-dimethylaminopyridine in anhydrous chloroform followed by removal of the tert-butyldimethylsilyl protecting group by treatment with dry hydrogen chloride gas in anhydrous chloroform at 0° yields the desired 1-acyl-sn-glycero-3-phosphorylcholine. Various facets of the reactions involved in developing the synthetic procedures in this study are discussed.

Raman and infrared spectral studies of anhydrous potassium and rubidium carbonate

Raman and infrared spectra of anhydrous K 2CO 3 and Rb 2CO 3 were measured at 300 and at 80 K. Infrared transmission, multiple internal reflection and polarized specular reflection techniques were used to determine transverse optical (TO) and longitudinal optical (LO) mode frequencies. The observed vibrational spectra for both salts were in excellent agreement with a C 2h unit cell group analysis which suggests that the crystal structures of anhydrous K 2CO 3 and Rb 2CO 3 are isomorphous (Spare group: P2 1/c). Unlike Na 2CO 3, the K 2CO 3 and Rb 2CO 3 structures are not complicated by disordering of CO 3 = groups over two sets of non-equivalent sites. Studies of the isotopically substituted ions, 13C 16O 3 = and 12C 16O 2 18O =, were employed to confirm assignments.

Bridged Aziridines. iv. Lead Tetra-Acetate Oxidation of 6-Aminomethylcyclohepta-1, 3-Diene

Abstract Lead tetra-scetate oxidation of 6-aminomethylcyelohepta-1,3-diene 1 in benzene in the presence of anhydrous potassium carbonate gave the bridged aziridine 8 in good yield, the structural asignment of 8 being confirmed by its ready cleavage with acetic anhydride to the cleavage compound 11. Lead tetra-scetate oxidation of 6-aminomethylcyelohepta-1,3-diene 1 in benzene in the presence of anhydrous potassium carbonate gave the bridged aziridine 8 in good yield, the structural asignment of 8 being confirmed by its ready cleavage with acetic anhydride to the cleavage compound 11.

New intermediates and dyestuffs for synthetic fibres. Part V. By-products of the Ullmann condensation between 1-chloroanthraquinone and aniline

1-Chloroanthraquinone condenses with aniline in the presence of anhydrous potassium carbonate to give 1-anilinoanthraquinone and a variety of by-products, of which 5,8,13,14-tetrahydro-5-phenylnaphtho[2,3-phenazine-8,13-quinone (III) is the major component.

New Compounds: Derivatives of Some Imido Compounds Likely to Possess Therapeutic Activity

The synthesis of certain N-alkylated derivatives of hydantoin, barbituric acid, succinimide, and glutarimide is described. The alkylation was achieved either by direct fusion of the imide with the halo compound in the presence of anhydrous potassium carbonate or by heating the sodio derivative of the imide with the halo compound in the presence of dimethylformamide as solvent. In the case of barbiturates, a dialkylated product was always obtained even when equimolecular amounts of reactants were used.

Experiments with Khellin. I. The Preparation of Desmethylkhellin and Some of its Derivatives

Khellin (2-methyl-5,8-dimethoxyfurochromone), C14H12O5 when refluxed with hydrobromic acid, yields a partially demethylated compound named by us as desmethylkhellin (2-methyl-5-hydroxy-8-methoxyfurochromone), C12H10O5. It occurs as deep yellow prisms, m. p. 201′. Methylation of desmethylkhellin with either diazomethane or methyl iodide results in the formation of khellin. The acetyl derivative of desmethylkhellin was prepared in the usual manner. The ethyl, n-propyl, n-butyl, allyl, carbethoxymethyl, acetamido, phenacyl, and beta-diethylaminoethyl derivatives were prepared by refluxing the appropriate halide with desmethylkhellin in acetone with anhydrous potassium carbonate. Hydrolysis of the carbethoxymethyl derivative yielded carboxymethyldesmethylkhellin.

Constitution of hibiscitrin. Part I

Analysis and study of acid hydrolysis show that hibiscitrin is a monoglucoside of hibiscetin. It undergoes complete methylation with dimethyl sulphate and anhydrous potassium carbonate in anhydrous acetone medium; on hydrolysing the methyl ether a O-hexamethyl hibiscetin is obtained which yields trimethyl gallic acid on fission with alkali. From this reaction and from other characteristic properties of the above partial methyl ether it is concluded that the free hydroxyl is in the 3-position and that hibiscitrin is a 3-glucoside.

Report on tests of steel plates: Made to the paint manufacturers of the United States

Novel heterocycle 3-cyano 6,9-dimethyl 4-imino 2-methylthio 4H pyrimido [2,1-b] [1,3] benzothiazole 3 has been prepared by using 2-amino 4,7-dimethtyl benzothiazole 1 and bis-methylthio methylene malononitrile 2.Compound 3 prepared from 2-amino 4,7-dimethyl benzothiazole 1 was refluxed with bis-methylthio methylene malononitrile 2 in presence of anhydrous potassium carbonate and N,N-dimethyl formamide as solvent. Compound 3 possesses replaceable methylthio functionality at 2-postion, which was replaced by using selected different nucleophiles like phenols/aryl amines/heteryl amines and compounds containing active methylene group to afford 2-substituted derivatives 4–7 of compound 3.Heterocyclic compounds containing benzothiazoles fused with pyrimidines, pyrazoles reported to possess activity against the different types of cancers. Compound 3 and it's selected derivatives 4–7 were screened for their in-vitro anticancer activity towards 60 Human cancer cell lines at National Cancer Institute, Maryland USA. Many compounds exhibited remarkable activity against 60 human cell lines.The compounds 3, 4-a, 4-d, 5-a, 6-a, 6-b exhibited maximum in-vitro anticancer activity against different cancers lines.