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214
FORMALDEHYDE
hy employing an acid-catalyzed reaction similar to that used in preparing
the dimethyl ether of dimethyloluron from urea (page 210), Kadowaki*
prepared the methyl ether of X-methyl-X'-methylohiron from monomethyl^
urea and X.X'-dimethyluron from .symmetrical dimethylurea:
H* I Efc I
C—N
c—x
/ \
0 C=0
\ /
c—y
Ha |
CH-OCH,
/ \
o c=o
\ /
c—x
a I
CHs
Methyl Ether of X-Metkyl- N\N'-Dimethyluron
X f -Me th yloil-Dim ethyl uron
These compounds are derivatives of dimethyloldirnethylureas.
Methylene bis-urea gives methylol and dimethylol derivatives with
formaldehyde 59 , reacting in much the same manner as urea itself.
Acetylurea gives methylene bis-acetylurea on treatment with formaldehyde
in cold concentrated sulfuric acid 22 . On hydrolysis with caustic, this
compound yields methylene bis-urea, which loses ammonia and cyclizes in
the presence of hydrochloric acid:
0
H ||
NHCONHj X—C
/ / \
H*C 4 HCI » H2C NH + NH4CL
\ \ /
XHCOXH* N—C
H II
O
Joint reactions of urea, formaldehyde, and secondary amines yield substituted
bis-(diaIk_ylaminomethyl)-ureas 29 . Derivatives of this type can
be made by adding the calculated quantity of dieth} T lamine or piperidine
and formaldehyde to a solution of urea in hot water:
XH2COXB2 4 2HN(CsHi)s -I- 2CH-0(aq) -*
(C2H5)2Nr-CH2-XHCOXH-CH2-X(C2H5)2 4 2H.0
XHiCONHa 4 2HXC6Hi« 4- 3CH20(aq) -+
C£H1QX'CH2.XHCONH-CH5-X T C5Hi0 4 2H.0
The diethylamide derivative is an oil which decomposes on heating. The
piperidine derivative is a crystalline product melting at approximately
136 D C. Substituted mono-(dialkylaminomethyl) derivatives can be obtained
from acylureas, formaldehyde, and secondary amines 30 .
RGOXHCONHt 4- CHaO(aq) 4 R'R"NH -» KCONHCOXHCH*NR'R'' 4 H20