formaldehyde - Sciencemadness Dot Org

REACTIONS WITH AMINO AND AMIDO COMPOUNDS 219
(0.8 mol CHsO) -while heating with a bath of boiling water for 10 minutes.
On cooling, the product gradually crystallizes in the course of two days and
may then be filtered from solution, washed with alcohol, and dried for 5
hours at 60 °C- The product as isolated apparently contains water of
crystallization and is a monohydrate of hexamethylolmelamine [CsX6fCHo
OHVHaO)]. The formation of this derivative is indicated thus:
^H* X(CH,OH)a
I I
C C
^ \ ^ \
N X X X
j || +6CH20(aq)- • | jj
H2X—C O-NHs (0H3OH) >X—C C—X(CHs OH).
\f X /
N X
On heating, hexamethylolmelamine hydrate melts at approximately 150 3 C
to give a clear liquid which is converted on continued heating to a clear,
coloriesSj water-insoluble resin.
All the methylolmelamines are water-soluble products which resinify on
heating. The products thus obtained are the well known melaminefonnaldehyde
resins. These resins are also made directly by heating
melamine and formaldehyde 113 . In general, \h.^ reactions of melamine
with formaldehyde resemble formaldehyde-amide reactions and the resin
chemistry involved is undoubtedly similar in many respects to the chemistry
of urea-formaldehyde resins (pages 211-213).
Aminoacetonitrile reacts with formaldehyde under alkaline conditions
in the same manner as other primary amines, giving trimeric methyleneaminoacetonitrile
62 :
/ \
NCCHa—X N—CH,CX
3NH5CH2CN + 3CH20(aq) > | ] + 3Ha0
C
\ /
N
CH2CX
This product is also obtained by the joint reaction of ammonium chloride
and sodium cyanide with formaldehyde 58 .
When polyajninonitriles, such as 2,2,11,114etramethyl-3?I0-diazododecane
dicarboxylonitrile, which is readily prepared by the reaction of
iiexamethvlenediamme with two mols of acetone cyanohydrin, are reacted