Phosphorus nitrile chloride adducts

Phosphorus nitrile chloride forms adduct (10) with DMF in the ratio 1 4, which is useful for the preparation of formamidines and azavinylogous formamidinium salts. It is supposed that the dehydration of primary amides to nitriles with (PNChls as well as the formation of 2-alkylbenzothiazoles from 2-(methylthio)anilides and (PNChls in the presence of triethylamine proceed via similar adducts." ... 

A still unresolved problem is the structure of the often used adducts from phosphorus trihalides and carboxylic acid amides, which might be described by the formulae (8) or (9). With the aid of in situ generated adducts of acid amides and PX3 amidines, isonitriles, quinazolinones, alkyl chlorides, aminomethylenediphosphonic acids, carbamoyl halides, triformylaminomethane, 1,3,4-oxadia-zoles, sulfides (from sulfoxides), nitriles (from primary nitro compounds)" and bromoqui-nolines (from methoxyquinolines)" have been prepared. 

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