molecules, forming C(8) chains propagating along ; see Fig. 4. C—H interactions also link the molecules into C(8) chains propagating along ; see Fig. 5. In addition, weak intramolecular – interactions, involving the benzene ring (C7–C12) and the pyrrolidine ring of the oxindole moiety (C20/C27/N2/C28/C33) stabilize the molecular packing [centroid-to-centroid distance = 3.621 (1) A ˚ ].
We have designed molecules which release alcohols upon exposure to UV light, independent of the reaction media, making it possible to liberate alcohols in a controlled manner in a variety of applications (Pika et al., 2000). Photolysis of 2-(2-isopropylbenzoyl)benzoate ester derivatives, (1), in an oxygen-free environment results in the liberation of the alcohol from the ester and formation of spirolactone (2) (Pika et al., 2003). The reaction mechanism for the release of the alcohol has been elucidated by time-resolved laser ¯ash photolysis (see scheme). Upon irradiation, the triplet excited state of (1) is formed, which decays by ef®cient intramolecular H-atom abstraction to form a 1,4-biradical, (3). Radical (3) undergoes intersystem crossing to form photoenols Z-(4) and E-(4). Isomer Z-(4) returns to the starting material through a 1,5-intramolecular H-atom transfer mechanism, whereas isomer E-(4) releases the alcohol through an intramolecular lactonization reaction and undergoes conrotatory electro- cyclic ring closure to form (2) (Wagner et al., 1991). We present here the crystal structure of (2).
Even if the differences in the substituents produce differences in lattice types, space group, cell metrics, etc, these molecular modifications do not seem to affect the type nor strength of the two relevant N—H N and C—H O intermolecular hydrogen bonds defining the crystal structures (Tables 1 and 2), which can thus be considered as essential for the crystal structure layout. In particular, those bonds involving C7 and N1 link glide-related molecules into similar one-dimensional strings along the shortest cell axis (Figs. 5 and 6). As already discussed, the other, relatively weaker, intermolecular C—
reaction of cyclohexanone and 2-aminocyclopent-1-enecarbo- nitrile. In the molecule of the title compound, the six-carbon ring displays a chair conformation, the six-membered 1,3- diaza ring and the cyclopentene ring both assume envelope conformations. Supramolecular aggregation is achieved by N—H O hydrogen bonds.
In the title molecule (Fig. 1), the benzofuran unit is essentially planar, with a mean deviation of 0.005 (1) Å from the least-squares plane defined by the nine constituent atoms. The dihedral angles between the mean plane of the benzofuran ring system and the pendant 4-fluorophenyl and phenyl rings are 1.50 (8) and 81.47 (6)°, respectively. In the crystal structure (Fig. 2), molecules are connected by weak C—H···O hydrogen bonds (Table 1) into chains extending along the a-axis direction, these chains are further packed into stacks by a sulfinyl–sulfinyl interaction (Choi et al., 2008)
The ability of the carbon-11-labelled analogue of (R)- N-(4-bromo-2-fluorophenyl)-6-methoxy-7-((1-methyl-3- piperidinyl)methoxy)-4-quinazolinamine ((R)-[ 11 C]PAQ) to detect levels of VEGFR2 in vivo is evaluated here in a transgenic mouse model of metastatic breast cancer, in which the expression of the polyoma middle T antigen (PyMT) oncoprotein is controlled by the mouse mammary tumour virus (MMTV). In the FVB genetic background, invasive mammary tumours and subsequent pulmonary metastases develop over 12 to 15 weeks. The model demonstrates gradual progression and significant stromal infiltration. It has been well characterized and shown to have a good translational potential . Outgrowth of micrometastases in the MMTV-PyMT model has been shown to be dependent on endothelial progenitor cell infiltration followed by a distinct growth acceleration which correlated with an increased vascularization . These features make this model attractive for evaluating novel PET radiotracers in a preclinical imaging setting. In this study, the MMTV-PyMT animals were injected with (R)-[ 11 C]PAQ and scanned with PET at the age of 11 to 15 weeks when the presence of primary tumours had been confirmed by palpation and metastatic events in lung tissue could be expected.
3-bromine-5-Chlorosalicylaldehyde (0.1 mmol, 23.55 mg) and 1-phenylethanamine (0.1 mmol, 12.1 mg) were dissolved in methanol (10 ml). The mixture was stirred for 30 min at room temperature to give a clear brown solution. After allowing the resulting solution to stand in air for 7 d, yellow block-shaped crystals of (I) were formed on slow evaporation of the solvent. The crystals were collected, washed with methanol and dried in a vacuum desiccator using anhydrous CaCl 2 (yield 54%). Analysis found: C 46.32%, H 3.35%, calculated for C 15 H 13 Br Cl N O : C 46.33%, H 3.35%.
To a stirred solution of 2-bromo-4-chloro-1-isothiocyanatobenzene (12.43 g, 50.0 mmol) in anhydrous dioxane (120 ml) dimethylamine (7.10 g of 33% solution in ethanol, 52.0 mmol) was slowly added in a drop-wise manner over 5 min. The reaction mixture was stirred at room temperature for an extra 1 h. The solid obtained was collected by filtration and washed with dioxane (2 x 20 ml) and dried. Recrystallization from ethyl acetate gave 3-(2-bromo-4-chlorophenyl)-1,1-di- methylthiourea (13.80 g, 47.0 mmol; 94%) as yellow crystals, m.p. 193–194 °C [lit. 184–185 °C (ethyl acetate); Smith et al. (1996)]. 1 H NMR (500 MHz, CDCl
3-Bromine-5-chlorosalicylaldehyde (0.1 mmol, 23.55 mg) and 1-benzylamine (0.1 mmol, 10.7 mg) were added to methanol (10 ml). The mixture was stirred for 30 min at room temperature to give a clear brown solution. After allowing the resulting solution to stand in air for 7 d, yellow block-shaped crystals of the title compound were formed on slow evaporation of the solvent. The crystals were collected, washed with methanol and dried in a vacuum desiccator using anhydrous CaCl 2 (yield 54%). Analysis found: C 51.76, H 4.0%; calculated for C 14 H 11 Br Cl N O : C 51.77, H 3.39%.
All reactions were monitored by TLC (Merck Silica gel) using petroleum ether, chloroform and ethyl acetate as developing solvents. The yields reported are calculated from analysis of the crude reaction mixtures. Melting points were recorded on an Expo-DI/QC/M/107 melting point apparatus and are uncorrected. Sonication was carried out using Ultrasonics 230 V AC, 50 Hz. Infrared spectrum was recorded on Bruker-FTIR model. UV spectra were recorded on a double beam spectrophotometer-systronics-2202 model. The compounds were detected by Hitachi UV lamp – F8T5 (254 nm).
molecular N—H O hydrogen bond with the amine group. The nitro substituent attached to the benzene ring is disordered over two sets of sites with occupancies of 0.694 (3) and 0.306 (3). The major component deviates significantly from the ring plane [dihedral angle = 53.6 (2) ]. In the crystal, the molecules are linked into a three- dimensional array by extensive – interactions involving both the naphthalene and benzene rings [range of centroid– centroid distances = 3.5295 (16)–3.9629 (18) A ˚ ] and C— H O interactions involving the methylene H atoms and the phenyl-attached nitro group.