Reaction of tryptamine 1 with dimethyl -3-methoxyallylidenemalonate 2 afforded N?-[4,4-bis (methoxycarbonyl)-1,3-butadienyl] tryptamine 3 which in combination with acetylchloride and pyridine in dichloromethane gave N?, N?-[acetyl]-[(4,4-dinethoxycarbonyl) 1,3butadienyl] tryptamine 4. Treatment of 3 with sodium hydroxide afforded 2H[N-(3-indolyl) ethyl] 2-oxo-3-methoxycarbonyl-1-pyridine 5. Cy...

Treatment of 4-heptafluoroisopropyl-2-methoxy-3,5,6-trifluropyridine (4 ) with aqueous ammonia in THF gave 2-amino-3,5-difluoro-4-heptafluoroisopropyl- 6-methoxy pyridine (5) in 7 1% yield. Chlorination of this amine with 'ButOCl at -16°C gave an unstable product, namely 2-dichloroarnino-3,5- difluoro-4-heptafluoroisopropyl-6-methoxy pyridine (6). Iodine-catalysed rearrangement of this dic...

Manually assigned keywords provide a valuable means for accessing large document collections. They can serve as a shallow document summary and enable more efficient retrieval and aggregation of information. In this paper we investigate keywords in the context of the Dutch Folktale Database, a large collection of stories including fairy tales, jokes and urban legends. We carry out a quantitative...

Computer programming today is far too dependent on one particular natural language, namely English. Mathematics is not dependent on English, and programming should not be, either. In order to eliminate the dependence of programming on English, we have constructed a programming language in which the keywords are replaced by symbols available on standard keyboards. Each of these symbols is chosen...

The article focuses on the role of keywords, their statistical data for determining thematic dominance when working with large arrays texts. description is based materials a typological linguistic study texts military songs, period 1939-1945, in English and Russian. selection keywords was carried out basis semantic, lexical-syntactic, morphological analysis, taking into account frequency use. u...

or Introduction Details of a planning study for USAF computer security requirements are presented. An Advanced development and Engineering program to obtain an open-use, multilevel secure computing capability is described. Plans are also presented for the related developments of communications security products and the interim solution to present secure computing problems. Finally a Exploratory...