The Absence of Quaternary Salt Formation between Phosphoryl Chloride and Pyridine1

1953 ◽  
Vol 75 (3) ◽  
pp. 751-753 ◽  
Author(s):  
B. M. Zeffert ◽  
P. B. Coulter ◽  
Rudolph Macy
Keyword(s):  
Quaternary Salt ◽  
Salt Formation ◽  
Phosphoryl Chloride

Steric Factors in Quaternary Salt Formation

1943 ◽  
Vol 65 (10) ◽  
pp. 1841-1845 ◽  
Author(s):  
Weldon G. Brown ◽  
Sherman Fried
Keyword(s):  
Quaternary Salt ◽  
Salt Formation ◽  
Steric Factors

‘Green' Synthesis of 2-Substituted 6-Hydroxy-[3H]-pyrimidin-4-ones and 4,6-Dichloropyrimidines: Improved Strategies and Mechanistic Study

2015 ◽  
Vol 68 (5) ◽  
pp. 814 ◽  
Author(s):  
Andreas Opitz ◽  
Werner Sulger ◽  
Ewald Daltrozzo ◽  
Rainer Koch
Keyword(s):  
Strong Acid ◽  
Nitrogen Heterocycle ◽  
Mechanistic Study ◽  
Salt Formation ◽  
Phosphoryl Chloride ◽  
One Pot ◽  
General Applicability ◽  
Aqueous Sodium Carbonate ◽  
Weak Complexes ◽  
First Time

An improved route to 2-substituted 6-hydroxy-[3H]-pyrimidin-4-ones 4 and to 2-substituted 4,6-dichloropyrimidines 5 is reported. Without using highly toxic reactants, compounds 4 can be prepared conveniently in a one pot synthesis on a one mol scale with average yields up to 80 %. 4,6-Dichloropyrimidines 5, which are usually prepared in small quantities, are synthesized with average yields of 80 %, using up to 80 g of starting material. The mechanism of the chlorination of 4 is investigated computationally for the first time. The results suggest that the chlorination with phosphoryl chloride occurs in an alternating phosphorylation–chlorination manner (pathway 1) which is preferred over a sequence which starts with two phosphorylations. The investigated 4,6-dichloropyrimidines described herein form strong complexes with dichlorophosphoric acid but weak complexes with hydrochloric acid (generated during workup). These latter complexes explain the necessity of using aqueous sodium carbonate during the working up. In order to prevent possible formation of pyrimidinium salts between intermediates or the final dichloropyrimidines and unreacted hydroxypyrimidone, the latter could be deactivated with a strong acid such as dichlorophosphoric acid, thus allowing chlorination but prohibiting salt formation. Because of its general applicability to all nitrogen heterocycle chlorinations with phosphoryl chloride, the proposed route to dichloropyrimidines without solvent or side products, using less toxic reactants, is of general synthetic interest.

Quaternary Salt Formation of Substituted Oxazoles and Thiazoles1

1960 ◽  
Vol 82 (1) ◽  
pp. 186-189 ◽  
Author(s):  
Vernon N. Kerr ◽  
Donald G. Ott ◽  
F. Newton Hayes
Keyword(s):  
Quaternary Salt ◽  
Salt Formation

scholarly journals Challenges of Mechanochemistry: Is In Situ Real-Time Quantitative Phase Analysis Always Reliable? A Case Study of Organic Salt Formation

2017 ◽  
Vol 4 (9) ◽  
pp. 1700132 ◽  
Author(s):  
Adam A. L. Michalchuk ◽  
Ivan A. Tumanov ◽  
Sumit Konar ◽  
Simon A. J. Kimber ◽  
Colin R. Pulham ◽  
...  
Keyword(s):  
Real Time ◽  
Phase Analysis ◽  
Organic Salt ◽  
Quantitative Phase Analysis ◽  
Salt Formation ◽  
Quantitative Phase
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