Showing papers on "Diazomethane published in 1971"

α-Heterodiazoalkanes and the Reactions of Diazoalkanes with Derivatives of Metals and Metalloids

Abstract: Publisher Summary This chapter focuses on α-heterodiazoalkanes and the reactions of diazoalkanes with derivatives of metals and metalloids. Interaction of mercury, silver, or lithium diazo compounds and halides or sulfides, results in salt elimination to yield the appropriate α-heterodiazoalkane. The action of nitrous acid on α-heteroamino compounds provides a synthetic route, but this procedure is limited to compounds having an amino function adjacent to an electron-withdrawing group. The α-heterodiazoalkanes containing an α-keto group may be converted into the corresponding diazomethane by treatment with acid or base, but the yields are low. All the compounds are intensely colored, and range from yellow to red. Their stability is dependent on the size and nature of the substituent groups; the α-heterodiazomethanes with only one hydrogen atom replaced are the least stable. Diazomethane rarely displays such reactivity, since much of its chemistry is dominated by the facility with which nitrogen is eliminated.

Derivatives of polyene macrolide antibiotics

Abstract: Derivatives of amphoteric polyene macrolide antibiotics which carry, on the lactone ring, a carboxyl group and an amino sugar characterized by a primary amine group, consist of (a) the methyl, ethyl or propyl ester formed by esterification of the carboxyl group, and (b) salts of such polyene esters constituted as acid addition salts formed with the amine group. The derivatives (a) and (b) have effective antimicrobial activity, e.g. antifungal potency, comparable to the base antibiotics, and the acid salts (b), produced by suitable acids, e.g. hydrochlorides, can be made to have good water solubility which is normally unattainable with the base compounds and is of special advantage in a compound which retains strong activity. Other addition salts are also of value, for example to provide lipid-soluble forms of these antifungal polyenes. Esterification of these chemically sensitive antibiotics is unusually successful using diazomethane, diazoethane or diazopropane with tetrahydrofurane as solvent to produce the ester dissolved therein, avoiding degradation of the base antibiotic or of its potency.

Reactions of bis(trifluoromethyl)diazomethane with zerovalent nickel, palladium, and platinum complexes

Abstract: Bis(trifluoromethyl)diazomethane reacts with zerovalent Ni, Pd, or Pt complexes to afford compounds L2[graphic omitted]·N : C(CF3)2(M = Ni, L = ButNC or PPh3, L2= 1,5-C8H12; M = Pd, L = ButNC or C6H11NC; M = Pt, L = PPh3); the structure of the platinum complex was established by a single crystal X-ray diffraction study.

Umsetzungen von Diazoalkanen mit Chinonen und α‐Diketonen, XVII. Abfangen intermediärer 1:1‐Additionsprodukte aus Diazomethan und Isatinen bzw. Indandionen‐(1.2)

Abstract: Durch Abfangen mit Acetylendicarbonsaure-dimethylester oder Tetrahalogen-o-benzo-chinonen lies sich nachweisen, das bei der Einwirkung Methanol-freier Diazomethanlosung auf Isatine 1b-d und Indandione 9a-d Aldol-artige 1:1-Additionsprodukte 5b-d bzw 10a-d („Diazo-aldole”) entstehen. Zusatz von Methanol katalysiert die N2-Abspaltung und damit die Folgereaktionen. Reactions of Quinones and α-Dicarbonyl Compounds with Diazoalkanes, XVII. Trapping of Intermediary 1:1-Addition Products from the Reaction of Diazomethane with Isatines or Indane-1.2-diones By trapping with dimethyl acetylenedicarboxylate or tetrahalo-o-benzoquinones it was shown that treatment of isatines 1b-d and indanediones 9a-d with methanol-free diazomethane solutions leads to aldolic 1:1 adducts 5b-d and 10a-d („diazo-aldoles”), respectively. Addition of methanol catalyses N2-elimination, thus resulting in further reactions.

Partricin methyl ester

Abstract: METHYL PARTRICIN, A NEW POLYENIC ANTIBIOTIC AGENT IS DESCRIBED HEREIN. THIS MATERIAL IS OBTAINED BY THE REACTION OF PARTRICIN WITH DIAZOMETHANE. IT POSSESSES GOOD ANTIFUNGAL ACTIVITY WITH LOW TOXICITY.

The chemistry of cyanoacetylenes. Part IX. Preparation of pyrazole derivatives via 1,3-dipolar cycloaddition reactions of cyanoacetylenes with diazomethane, N-phenylsydnone, and diphenylnitrilimine

Abstract: Cyanoacetylene and chlorocyanoacetylene and the corresponding propiolamides reacted with diazomethane to give exclusively 5-cyano- or-carbamoyl-pyrazoles in good yields. Although cyanoacetylenes did not react with N-phenylsydnone in refluxing benzene, in chlorobenzene at ca. 110° the expected pyrazoles were obtained. Irradiation of 2,5-diphenyltetrazole in the presence of cyanoacetylene afforded 1,3-diphenylpyrazole-5-carbonitrile. The adducts formed from cyanoacetylenes and hydrazines could not be cyclised.

Reactivity of the Exocyclic Double Bond in 5-arylidene derivatives of barbituric and thiobarbituric acids

Abstract: The exocyclic double bond in 5-arylidene barbituric (3) and thiobarbituric acid (5) derivatives undergoes addition reactions with GRIGNARD reagents yielding the compounds 4 and 6. Also they react with ethereal diazomethane to give the corresponding cyclopropane compounds 7 and 8. Similarly, addition reaction was observed when the compounds 3 and 5 are treated with primary and secondary amines giving 11 and 12, respectively.

Chemically activated 1,1‐dimethylcyclopropane from photolysis of isobutene–neopentane–diazomethane–oxygen mixtures

Abstract: A study of the structural isomerization rate of chemically activated 1,1-dimethylcyclopropane from singlet methylene addition to the double bond of isobutene is reported. Singlet methylenes were produced from the 4358- and 3660-A photolysis of diazomethane in the presence of added oxygen. Theoretical rates calculated via RRKM theory are in excellent agreement with experiment for calculations utilizing activated complex structures and critical energies consistent with known thermal Arrhenius parameters, and excitation energies consistent with previous determinations of ΔH(CH2) + E*(CH2) = 116.1 and 112.6 kcal/mole for diazomethane photolyses at 3660 and 4358 A, respectively.

Thermal and Photochemical Ring Expansion of Some Phosphole Derivatives

Abstract: Pyrolysis and photolysis of 3,4,5-triphenyl-4-phosphabicyclo[3.1.0]hex-2-ene-4-oxide and the 1:1 adduct of diazomethane with 1,2,5-triphenylphosphole oxide lead to the formation of compounds of for...

Preparation of methyl derivatives of some organic acids for analysis by gas-liquid chromatography.

Abstract: One microgram to 1 mg of organic acid was completely converted to its methyl derivative when it was dissolved in methanol and treated with an excess of ethereal diazomethane. Single products were o...

Umsetzungen von vic. Tricarbonylverbindungen mit aliphatischen Diazoverbindungen, V. Umsetzungen offenkettiger Diaryltriketone

Abstract: Die Triketone 2 liefern mit Diazomethan und -athan Diaroyloxirane 7, wahrend mit Phenyl-Pyridyl-(3)- und Pyridyl-(4)-diazomethan vorzugsweise Insertionsprodukte 8 entstehen. Letztere erweisen sich als Enole. Mit o-Phenylendiamin erhalt man aus den Benzyl-Insertions-produkten 8 jedoch die von der Ketoform abgeleiteten Chinoxaline 10, wahrend bei der Einwirkung von o-Phenylendiamin auf die Picolyl-Insertionsprodukte 11 und 13 unter Spaltung des Molekuls neben den Picolinen die 3-Aryl-chinoxalinone 12 und die 2-Arylbenzimidazole 20 entstehen. Hierfur wird ein Reaktions-Schema vorgeschlagen. Reactions of Vicinal Tricarbonyl Compounds with Aliphatic Diazo Compounds, V. Reactions of Ring-open Diaryltriketones Diazomethane and -ethane react with the triketones 2 to give the diaroyloxiranes 7, whereas phenyl-, 3-pyridyl-, and 4-pyridyldiazomethanes give predominantly the insertion products 8, which are enols. With o-phenylenediamine, however, quinoxalines 10 are obtained, derived from the keto form of the benzyl insertion products. Treatment of the picolyl insertion products 11 and 13 with o-phenylenediamine leads, via splitting off the picolines 17 and 19, to the formation of the 3-arylquinoxalinones 12 and the 2-arylbenzimidazoles 20, respectively. A mechanism for these reactions is proposed.

4-substituted 3-cephem compounds

Abstract: 4-DIAZOACETYLCEPHALOSPORINS ARE PREPARED FROM THE REACTION OF THE 4-CARBOXYLIC ACID CHLORIDES WITH DIAZOMETHANE THESE COMPOUNDS ARE INTERMEDIATES USEFUL FOR PREPARING 4-ACETIC ACIDS AND 4-HALOACETYL COMPOUNDS WHICH HAVE ANTIBACTERIAL ACTIVITY 4-HYDROXYMETHYLCEPHALOSPORINS ARE PREPARED BY REDUCTION OF THE 4-CARBOXYLIC ACID CHLORIDES

Covalent hydration in the tetrazolo [1,5-c]quinazoline series (structure of the products of hydration of 5-methyl(phenyl)-9-bromotetrazolo[1,5-c]-quinazolines)

Abstract: 1(2)-Methyl-5-(2-acylamino-5-bromophenyl)tetrazoles (VIa,b), the structures of which were proved by alternative synthesis, were obtained by the action of diazomethane on the products of covalent hydration of 5-methyl(phenyl)-9-bromotetrazolo[1,5-c]quinazolines. A comparison of the IR and UV spectra of the hydration products and VIa and VIb confirms that the former have the 5-(2-acylamino-5-bromophenyl)tetrazole structure (IIa,b) in the crystalline state and in solution.