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141.
Tomohisa Nagamatsu Keiichi Kinoshita Kenji Sasaki Taiji Nakayama Takashi Hirota 《Journal of heterocyclic chemistry》1991,28(2):513-515
A simple and highly efficient methodology for the synthesis of 1,2,4,5-tetrahydro[1]benzothiepino[4,5-e]-imidazo[1,2-c]pyrimidine ( XI ) having a novel ring system via 4-substituted 5,6-dihydro[1]benzothiepino-[5,4-d]pyrimidines VII-X is described. The anti-platelet aggregation activity for it and its related compounds against collagen-induced aggregation of rabbit blood platelets in vitro was found. 相似文献
142.
Various 6-substituted 9-benzyl-8-hydroxypurines were synthesized in order to investigate the structure-activity relationship at the 6-position of 9-benzyl-8-hydroxyadenine (1), which is a lead compound for the screening of interferon (IFN)-inducing activity. 6-Unsubstituted, mercapto-, methylthio- and hydroxy-9-benzyl-8-hydroxypurines (2-5) were prepared from 5-amino-1-benzyl-4-cyano-2-hydroxyimidazole (9). Synthesis of a 6-methoxy analog (6) was conducted from 5-amino-4-benzylamino-6-chloropyrimidine (13). 6-Alkylamino and acylaminopurines (7 and 8) were also prepared by alkylation and acylation of 1, respectively. Since these compounds (2-8) indicated no activity, it was found that a free amino group of 1 is required for the expression of IFN-inducing activity. 相似文献
143.
Tubiferal A, a novel rearranged triterpenoid lactone, has been isolated from field-collected fruit bodies of the myxomycete, Tubifera dimorphotheca, and its structure elucidated by spectral data. Tubiferal A (1) possesses a 9,10-secocycloartan-16,21-olide skeleton, and this new compound exhibited a reversal effect of vincristine (VCR) resistance (more than 4-fold) against VCR-resistant KB cell lines. Tubiferal B (2), corresponding to the seco acid of 1 was also isolated, but showed no comparable activity. 相似文献
144.
The PdCl(2)-catalyzed cyclization of amino allylic alcohol 16 gave the cyclized product 17a with excellent diastereoselectivity. The versatility of compound 17a as the building block for synthesizing cis-2,6-disubstituted piperidine alkaloids has been demonstrated by a total synthesis of (-)-cassine (1). [reaction--see text] 相似文献
145.
Using CO2 and N2O lasers, we have measured and assigned nineteen ν4 and nine ν6 rotation-vibration resonances of the type ΔM = 0 and M = J. These transitions were combined with the zero-field pure rotational spectra in order to determine the two fundamental vibrational frequencies, the rotational constants of both excited states, the Coriolis coupling constant, and the dipole moments of each of the three states. The ground-state rotational constants and centrifugal distortion constants were taken from a microwave study and the centrifugal distortion constants of the excited states were assumed equal to those of the ground state. The following results were obtained (standard deviations in parentheses):
938.0345 (6) | 989.2519 (18) | (cm?1) | ||||
139 579 (150) | 143 323 (150) | (MHz) | ||||
31 873.6 (5) | 32 379.5 (7) | (MHz) | ||||
26 242.9 (6) | 25 994.4 (8) | (MHz) | ||||
136 178 (770) | (MHz) | |||||
μ | 2.319 (10) | 2.347 (4) | (D) | |||
μ(ground state) | 2.3464 (8) | (D) |