Fluorine-containing heterocycles: XIX. Synthesis of fluorine-containing quinazolin-4-ones from 3,1-benzoxazin-4-ones

Reactions of fluorine-containing 3,1-benzoxazin-4-ones with ammonium acetate, hydrazine, and heteroaromatic amines gave new 3H-, 3-amino-, and 3-hetarylquinazolin-4-ones, respectively. Differences in the conditions of formation of benzoxazinones from anthranilic acids with different fluorination patterns and in the reactions of fluorinated 3,1-benzoxazinones with nitrogen-centered nucleophiles were revealed.     

Fluorine-containing heterocycles: XVIII. Monofluoro derivatives of quinazolines and 1,3-benzothiazin-4-ones

5- and 7-Fluoro-substituted quinazolines and 1,3-benzothiazin-4-ones were synthesized starting from 2-amino-6-fluorobenzonitrile and mono- and difluoro-substituted benzoic acid derivatives. The reactivities of di- and tetrafluoro-substituted benzoyl chlorides and benzoyl isothiocyanates in cyclocondensations leading to fluorinated quinazolines and 1,3-benzothiazines were compared.     

A convenient procedure for introducing arylsulfanyl and heterylsulfanyl groups into the 5 position of the oxazole ring

Available (2-aryl-5-mesyl-1,3-oxazol-5-yl)triphenylphosphonium salts readily react with sodium thiophenolates and their heterocyclic analogs by way of substitution of the mesyl group by an arylsulfanyl or a heterylsulfanyl group. Treatment of the products with sodium hydroxide results in their mild dephosphorylation, which was used for preparative synthesis of a series of 2-aryl-5-arylsulfanyl(heterylsulfanyl)-1,3-oxazoles.Translated from Zhurnal Obshchei Khimii, Vol. 74, No. 9, 2004, pp. 1524–1528.Original Russian Text Copyright © 2004 by Golovchenko, Brovarets, Drach.This revised version was published online in April 2005 with a corrected cover date.     

Channeling of 1.1 GeV/c protons and pions

Channeling effects have been observed for 1.1 GeV/c protons and pions transmitted through a 1 mm thick germanium single crystal.     

Channeling of protons,pions and deuterons in the GeV region

Strong directional effects have been observed when 1.15 and 1.35 GeV/c protons, π⁺ and π^?, and deuterons penetrate through germanium crystals. Transmission, wide-angle scattering, and an attempt to do blocking distributions are obtained from experiments using position-sensitive drift chambers. Corresponding measurements of energy loss in germanium crystals are also presented. These experimental results are compared to theory for energy loss, and satisfactory agreement is obtained.