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Replacement of halogen by phosphorus

Replacement of halogen by phosphorus by means of elemental phosphorus... [Pg.716]

Phosphorus pentasulfide (s. a. under C H N) Replacement of halogen by sulfur Fluorothiocarbonyl compounds... [Pg.168]

Similar results for the replacement of halogen on an olefinic linkage by phosphorus have been accomplished using dialkyl phosphites with palladium(O) catalysts.4179 Another reaction involving replacement of a vinylic halide by phosphorus utilizes palladium catalysis with a trimethylsilyl-substituted phosphine (Figure 6.19).80... [Pg.175]

Reductive removal of halogen substituents has been of value in the synthesis of pyrimidines and purines since the time of Fisher (1899). Natural purines were de-oxygenated in a sequence of reactions involving the replacement of hydroxyl by chlorine through the reaction with phosphorus pentachloride and the reduction using zinc dust and water [152], 2-Chloropurines 45 are not reduced under these conditions. The 2-iodopurines are however reduced by zinc and water [152]. The elec-... [Pg.125]

A large number of 9-chloro and 9-bromo bases has been prepared by the action of phosphorus halides on the various alkaloids (11-14, 56, 97, 134, 135, 151, 166, 167). It seems probable that the replacement of hydroxyl by halogen in these reactions takes place with inversion. The hydrolysis of the halides, which is best carried out with silver nitrate in dilute nitric acid, also appears to involve a change in conflguration at... [Pg.34]

Phosphorus pentahalide Replacement of oxygen by halogen in N-heterocyclics... [Pg.155]

Pyridine/phosphorus pentasulfide Replacement of halogen and oxygen by sulfhydryl... [Pg.161]

The hydroxyl groups of 5-hydroxypyrazoles (498) are readily replaced by halogens by the action of phosphorus halides. [Pg.100]

See other pages where Replacement of halogen by phosphorus is mentioned: [Pg.716]    [Pg.717]    [Pg.719]    [Pg.720]    [Pg.720]    [Pg.721]    [Pg.722]    [Pg.723]    [Pg.725]    [Pg.725]    [Pg.725]    [Pg.727]    [Pg.728]    [Pg.729]    [Pg.716]    [Pg.717]    [Pg.719]    [Pg.720]    [Pg.720]    [Pg.721]    [Pg.722]    [Pg.723]    [Pg.725]    [Pg.725]    [Pg.725]    [Pg.727]    [Pg.728]    [Pg.729]    [Pg.41]    [Pg.215]    [Pg.168]    [Pg.1201]    [Pg.1563]    [Pg.293]    [Pg.361]    [Pg.343]    [Pg.127]    [Pg.35]    [Pg.242]    [Pg.222]    [Pg.86]    [Pg.209]    [Pg.74]    [Pg.262]    [Pg.149]    [Pg.311]    [Pg.129]    [Pg.322]    [Pg.186]    [Pg.422]   


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Replacement halogens

Replacement of halogen

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