(E)-3-[4-(Dimethyl­amino)­benzyl­idene]-2,3-di­hydro-1H,9H-pyrrolo­[2,1-b]quinazolin-9-one

The title compound, C20H19N3O, was obtained by condensation of 2,3-dihydro-1H,9H-pyrrolo­[2,1-b]quinazolin-9-one (alkaloid de­oxy­vasicinone, isolated from Peganum Harmala) with 4-(dimethyl­amino)­benzaldehyde in the presence of sodium methoxide. The 2,3-dihydro-1H,9H-pyrrolo­[2,1-b]quinazolin-9-one part of the mol­ecule is roughly planar (r.m.s. deviation = 0.0178 Å) and is essentially coplanar with the benzil­idene ring (r.m.s. deviation = 0.0080 Å), forming a dihedral angle of 5.0 (1)°. The crystal structure is stabilized by two aromatic π–π stacking inter­actions observed between the benzene rings of neighboring mol­ecules [centroid–centroid distance = 3.7555 (19) Å

Deuterium Exchange of the α-Methylene Group Protons in the Quinazolones. III. Environment Influence on the Exchange Rate

By 1H NMR spectroscopy methods the exchange process of α-methylene group protons of deoxyvasicinone by deuterium atoms in the medium of CD3OD+NaOH and CD3OD+CD3COOD depending on NaOH concentration and temperature of the solution and CD3COOD have been investigated. It was shown that NaOH and CD3COOD have exchange initiator character, and their effect on the concentration are linear to D-exchange rate. The exponential dependence on temperature allowed us to determine the potential barrier of the initiation of the D- exchange process for deoxyvasicinone in the CD3COOD

(E)-3-Propoxymethyl­idene-2,3-dihydro-1H-pyrrolo[2,1-b]quinazolin-9-one monohydrate

The title compound, C15H16N2O2·H2O, was synthesized via the alkyl­ation of 3-hydroxy­methyl­idene-2,3-dihydro-1H-pyrrolo[2,1-b]quinazolin-9-one with n-propyl iodide in the presence of sodium hydroxide. The organic mol­ecule and the water mol­ecule both lie on a crystallographic mirror plane. In the crystal structure, inter­molecular O—H⋯O and O—H⋯N hydrogen bonds link the components into extended chains along [100]

6,7,8,9,10,11-Hexahydro-13H-azocino[2,1-b]quinazolin-13-one

The title compound, C14H16N2O, is a synthetic analogue of quinazolone alkaloids with pyrrilo, pyrido and azopino rings. The quinazolinic part of the mol­ecule is generally planar within 0.037 (3) Å; the eight-membered ring exhibits an inter­mediate conformation between the chair and boat forms as it is typical for cyclo­octene rings. An ethyl­ene group of the azopino ring is disordered over two positions with a refined occupancy ratio of 0.910 (7):0.090 (7). In the crystal, the H atoms of the aromatic rings form weak C—H⋯O and C—H⋯N hydrogen bonds. One C—H⋯O hydrogen bond leads to the formation of a one-dimensional chain. Another C—H⋯O and a C—H⋯N bond link these chains, generating a three-dimensional network

2-Methyl-4-oxo-6,7,8,9-tetrahydro­thieno[2′,3′:4,5]pyrimidino­[1,2-a]pyridine-3-carboxylic acid

There are two independent mol­ecules in the asymmetric unit of the title compound, C12H12N2O3S. With the exception of the methyl­ene groups, a mean plane fitted through all non-H atoms of each mol­ecule has an r.m.s. deviation of 0.035 Å for one mol­ecule and 0.120 Å for the second. In one of the independent mol­ecules, the methyl­ene groups was refined using a disorder model with an occupancy ratio of 0.53:0.47 (14). Each molecule features an intra­molecular O—H⋯O hydrogen bond, which generates an S(7) ring

2,3-Dihydro­pyrrolo­[2,1-b]quinazoline-9(1H)-thione

In the crystal, mol­ecules of the title compound, C11H10N2S, are connected by C—H⋯N inter­actions around threefold axes. Furthermore, they form stacks along the c axis showing π–π inter­actions between pyrimidine rings [centroid–centroid distance = 3.721 (1) Å]. The central ring is essentially planar with an r.m.s. deviation of 0.007 Å. The five-membered ring adopts an envelope conformation with the flap atom deviating by 0.241 (4) Å from the mean plane (r.m.s. deviation = 0.002 Å) through the other four ring atoms

Математическое моделирование зажигания растительного покрова в результате разрыва газопровода

В данной работе представлена математическая модель и численные результаты зажигания полога леса в результате разрыва газопровода с образованием "огненного шара" с учетом структурных особенностей и характеристик лесного горючего материала, а также особенности среды, в которой происходит тепловое излучение. Проблема взрывов в нефтехимической промышленности с образованием ОШ является сегодня актуальной для многих стран, включая и РФ. Разработана компьютерная программа, которая используется для определения безопасных расстояний от объектов повышенной опасности (ОПО).This paper presents a mathematical model and results of calculations of the ignition of forest canopy as a result of the gas pipeline rupture with the formation of a fireball taking into account the structural features and characteristics of forest fuel material, as well as the features of the environment in which thermal radiation occurs. The problem of explosions in the petrochemical industry with the formation of the Fire Ball is relevant for many countries now, including the Russian Federation. A computer program has been developed that is used to determine the safe distances from high-risk objects

11-(2-Oxopyrrolidin-1-ylmeth­yl)-1,2,3,4,5,6,11,11a-octa­hydro­pyrido[2,1-b]quinazolin-6-one dihydrate

In the crystal structure of the title compound, C17H21N3O2·2H2O, water mol­ecules are mutually O—H⋯O hydrogen bonded and form infinite chains propagating along the b axis. Neighboring chains are linked by the quinazoline mol­ecules by means of O—H⋯O=C hydrogen bonds, forming a two–dimensional network

3-Benzyl-6-(2-chloro­benzo­yl)-1,3-benzoxazol-2(3H)-one

In the title compound, C21H14ClNO3, the benzoxazolone ring system is planar (r.m.s. deviation = 0.022 Å) and forms dihedral angles of 75.38 (10) and 65.92 (13)° with the mean planes of the chloro­benzoyl (r.m.s. deviation = 0.045 Å, excluding O atom) and benzyl (r.m.s. deviation = 0.023 Å) groups. The observed structure is stabilized by weak C—H⋯O hydrogen bonds and weak inter­molecular C—H⋯π inter­actions

1-[(4-tert-Butyl­phen­yl)sulfon­yl]-1H-benzimidazole

The title compound, C17H18N2O2S, was synthesized by aryl­sulfonyl­ation of 1-hy­droxy­methyl-1H-benzimidazole in the presence of triethyl­amine. The benzimidazole and benzene rings form a dihedral angle of 84.1 (1)°. The tert-butyl group was treated as rotationally disordered over two orientations in a 0.51 (2):0.49 (2) ratio. In the crystal, weak inter­molecular C—H⋯O hydrogen bonds link the mol­ecules into chains propagating in [010]