Phosphorus pentachioride

D) Ethyl 2-Chloro-6-(n)-Propyl-lsonicotinate The 40 grams of the acid just obtained are treated with 80 grirrTs of phosphorus oxychloride and 95 grams of phosphorus pentachioride. The phosphorus oxychloride is distilled and the reaction mixture is treated with 400 grams of absolute alcohol. 40 grams of chlorinated ester, having a BP of 115°-116°C/2 mm, are obtained. 

The product is thermally unstable, however, and at 150—180 °C in vacuo a molecule of phosphorus pentachioride is lost, leaving NC- CCl2 - CHa- N=PCl3. 

The products from the reactions with phosphorus pentachioride vary even with the nature of the aryl group. Thus, the p-chlorophenyl compound gave a product analogous to (6), but it was accompanied by the dimeric phosphazene, [p-ClCeHiNPClsJa. 

A First, a reaction with phosphorus oxychloride and phosphorus pentachioride can be used to convert 2-pyridone into 2-chloropy= ridine. and then this compound is subjected to an addition-elimination reaction with methoxide ion (from sodium methoxide) (Scheme 2,26). Note chloride is a much better leaving group than methoxide. 

Substitution reactions involving 3/S-hydroxy-A -steroids and their derivatives require special mention. Cholesterol reacts with a variety of halogenating agents, including thionyl chloride / StJ, phosphorus pentachioride [81], haHdes of aluminium or titanium [82], 2-chloro-i,i,2 trifluoroethyl di-ethylamine [83] and triphenylphosphine dibromide [55], to... 

Example 5 Phosphorus Pentachioride (PCI3) and Sulfur Hexafluoride(SF )... 

This is a test for an OH group. Steamy acidic fumes are given off when phosphorus pentachioride is added to the dry organic substance. 

Phosphorus Pentachioride 93 8 Exposure temperature is maximum recommended service temperature Kynar Atochem... 

Phosphorus Trichloride (Phosphorous chloride). PCI3, mw 270.73 colorl, clear fuming liq, mp —111.8°, bp 76°, d 1.547g/cc. Decomps rapidly in moist air. -Dissolves in w or ale with decompn and liberation of much heat. Sol in benz, chlf, eth and C disulfide. Prepd by passing a current of dry chlorine over gently heated P, which ignites. The trichloride, admixed with some pentachioride, distills over. A small amt of Pis added and the whole distilled (Refs 9 10)... 

Table 3 quadruple resonance frequencies for phosphorus and antimony pentachiorides... 

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