Alcoholysis of N-acetoxy-N-alkoxycarbamates. Synthesis of NH-N,N-dialkoxyamines from N,N-dialkoxycarbamates

The alcoholysis of N-acetoxy-N-alkoxycarbamates by methanol or ethanol at 20 – 40 °C yields N,N-dialkoxycarbamates and acetic acid. At the lower temperature the competitive formation of N,N’-bis(alkoxycarbonyl)-N,N’-bis(alkoxy)hydrazines can occur. The alkaline hydrolysis of N,N-dialkoxycarbamates yields NH-N,N-dialkoxyamines

Spectral analysis of X-ray pulsars with the INTEGRAL observatory

We studied spectra for 34 accretion-powered X-ray and one millisecond pulsars that were within the field of view of the INTEGRAL observatory over two years (December 2002 - January 2005) of its in-orbit operation and that were detected by its instruments at a statistically significant level (>8 sigma in the energy range 18-60 keV). There are seven recently discovered objects of this class among the pulsars studied: 2RXP J130159.6-635806, IGR/AX J16320-4751, IGR J16358-4726, AX J163904-4642, IGR J16465-4507, SAX/IGR J18027-2017 and AX J1841.0-0535. We analyze the evolution of spectral parameters as a function of the intensity of the sources and compare these with the results of previous studies

New approach to N,N-dialkoxy-N'-arylureas and N,N-dialkoxycarbamates

Methanolysis of N-chloro-N-alkoxy-N'-arylureas in the presence of silver trifluoroacetate gives the corresponding N,N-dialkoxy-N'‑arylureas, whereas N-chloro-N-alkoxycarbamates react with alcohols in the presence of silver trifluoroacetate to afford N,N-dialkoxycarbamates

Methanolysis of N-acetoxy-N-n-propyloxy-N’,N’-dimethylurea in different conditions

The methanolysis of N-acetoxy-N-n-propyloxy-N’,N’-dimethylurea in the presence of strong acids at room temperatures or in the boiling methanol yields N,N-dimethoxy-N’,N’-dimethylurea as final product. Primarily the nucleophilic substitution acetoxy group at nitrogen on methoxy group arises. At second stage the transesterification of N,N-dialkoxyamino group of formed N-methoxy-N-n-propyloxy-N’,N’-dimethylurea take place

The properties and structure of N-chloro-N-methoxy-4-nitrobenzamide

The XRD study of N-chloro-N-methoxy-4-nitrobenzamide revealed the high pyramidality degree of its amide nitrogen atom in O–N–Cl moiety. N-Chloro-N-methoxy-4-nitrobenzamide reacts with AcONa in MeCN selectively forming N-acetoxy-N-methoxy-4-nitrobenzamide, whereas its methanolysis in the presence of AcONa yields N,N' bis(4-nitrobenzoyl)-N,N'-dimethoxyhydrazine

Pyramidal amide nitrogen in N-acyloxy-N-alkoxyureas and N-acyloxy-N-alkoxycarbamates

The XRD studies of N-acyloxy-N-alkoxyamides 1, 2 have revealed a highly pyramidal configuration of amide nitrogen in the O–N–O group

Synthesis and structure of N-alkoxyhydrazines and N-alkoxy-N',N',N'-trialkylhydrazinium salts

New types of 1,1,1-trialkyl-2-alkoxyhydrazinium chlorides and N-alkoxyhydrazines were obtained by reactions of N-chloro-N-alkoxyureas with trimethylamine or 1,4-diaza[2.2.2]bicyclooctane and by reactions of methyl N chloro-N-methoxycarbamate with potassium salt of N-acetylbenzenesulfonylamide. The XRD studies of N,N' bis(methoxycarbonyl)-N,N'-dimethoxyhydrazine, N'-methoxy-N'‑methoxycarbonyl-N-acetylbenzenesulfonylhydrazide and 1,1,1-trimethyl-2-methoxyhydrazinium perchlorate revealed the pyramidal configuration of the central nitrogen atoms in O–N–N geminal system, unusual elongation of N–N+ bond and shortening of N–OMe bond in 1,1,1-trimethyl-2-methoxyhydrazinium perchlorate

Synthesis, structure and properties of N-alkoxy-N-(1-pyridinium)urea salts, N-alkoxy-N-acyloxyureas and N,N-dialkoxyureas

N-Alkoxy-N-(1-pyridinium)urea salts 3, 4 have been prepared, the conversions of N-acetoxy-N-methoxyurea 7 into N,N-dimethoxyurea 8 and of N-n-propyloxy-N-(1-pyridinium)-N',N'-dimethylurea chloride 6 into N,N dimethoxy-N',N'-dimethylurea 11 were carried out. A high pyramidality of the amide nitrogen in O–N–X groups [X = N+C5H5, OMe, OC(O)C6H4Cl-p] has been revealed by XRD studies of ureas 3b, 8 and N-p chlorobenzoyloxy-N-n-butyloxyurea 9