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Binary freezing‐point diagrams for palmitic acid with various amines and with 2,6‐dimethyl‐gamma‐pyrone
Author(s) -
Mod Robert R.,
Magne Frank C.,
Skau Evald L.
Publication year - 1959
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1007/bf02639978
Subject(s) - chemistry , morpholine , benzylamine , 2 aminopyridine , palmitic acid , melting point , eutectic system , organic chemistry , pyridine , fatty acid , alloy
Summary In connection with the search for molecular compounds which might prove applicable in the purification of long‐chain fatty acids, freezing‐point data have been obtained for binary systems between palmitic acid and the following: ortho‐phenylenediamine, alpha‐picoline, 4‐amino‐2,6‐dimethylpyrimidine, 2,6‐dimethyl‐gamma‐pyrone, 2‐aminothiazole, benzylamine, morpholine, 3‐aminopyridine, and 4‐aminopyridine. The freezing‐point diagrams for the first four of these binary systems are of the simple eutectic type. All the others indicate the existence of at least one crystalline molecular compound containing one or more moles of palmitic acid to one of amine. 2‐Aminothiazole forms an equimolar compound. Both benzylamine and morpholine form an equimolar and an incongruently melting 2∶1 compound. The position of the amino group in the pyridine ring has a marked effect on the behavior of the aminopyridines. Unlike 2‐aminopyridine, which forms a 1∶1 and a 4∶1 compound with palmitic acid, 3‐aminopyridine forms only an equimolar compound and 4‐aminopyridine forms only 4∶1 and 2∶1 compounds. The latter exists in two polymorphic modifications.