formaldehyde - Sciencemadness Dot Org

REACTIONS WITH AMINO AND AMIDO COMPOUNDS 203
can also be reduced to raethylamines is indicated by the fact that dimethyleThanolamine
can be prepared by a low-temperature, catalytic hydrogenation
of the viscous liquid [probably dimethylolethanolamine," HOCH2-
ClIsNtGHaOHJa] which is obtained by dissolving paraformaldehyde
equivalent to two mols of formaldehyde in one mol of ethanolarnine*-.
The Mannich reaction and other joint reactions 3 * of formaldehyde with
primary or secondary amines and various polar compounds lead to the formation
of substituted aminomethyl derivatives.
Reactions of dimethylamine and formaldehyde with hydrogen cyanide 49 ,
isobutanol 95 , phenol 21 , and acetone 36 are typical:
iCE,)-XH 4- CH20(aq} -f HCX -* (CH^XCH-CX + HaO
{CJWoXH + CH20(aq) + (CH3^CHCH2OH -> (CH3)£NCH2OCH2CHfCH,}3 + HaO
(CHO^H + CH20(aq) + C6H5OH -> (CH^XH.C^OHfp) 4- HsO and
C6H5OCH2X(CH3L> + HaO
(CHdaNH + CH20(aq) + CH3COCH3 -• (CHa)2NCH3CH2COCH3 -f H*0
Production of alkyl propargylamines in high yields by the joint reaction
of formaldehyde, acetylene, and dialkylamines is claimed 93 :
R2NH + CH20(aq) + HCiCH -> RJNCHJC;CH -f H20
This reaction is carried out in acetic acid under pressure, using cuprous
chloride a a catalyst. 1,4-Di~(alkylamine-)-butinesJ RaXCHaC: CCH2-
NR2, are also formed in small amounts.
Methylamine, f ormaldehvde, and hydrogen sulfide react to form methvlthioformaldine,
(CHoJ3S2NCH3*°.
A joint reaction of formaldehyde, secondary, amines, and hydrogen selenide
has also been described 6 .
Aromatic Amines
Under ordinary conditions, the reaction of aniline with dilute formaldehyde
gives a mixture of products. However, with proper control anhydroformaldehyde
aniline (in .p. 140-141 °C) may be obtained as the principal
product 88 ' 117 . This compound, which is the trimer of the hypothetical
Schiff's base, methylene aniline, (C6H5N:CH2)3j probably has a cyclic
structure analogous to that of the trialkyl trimethylenetriamines 79 - 91 :
CeHs
I
N
/ \
HZC CH2
I I
C*HS—N N—C„Hfi
\ /
C
Hs
Anhydro-formaldehyde Aniline