Chemistry Reference
In-Depth Information
When aziridine 171 is added to an excess of phosgene, in the absence of an acid
acceptor, bis(2-chloroethyl)urea 172 is produced as the major product [109, 110].
H
N
H
N
Cl
Cl
NH
Cl
Cl
2
+
O
O
171
172
When equivalent amounts of aziridine and triethylamine in tetrachloromethane
are added to a solution containing 1 equiv. of phosgene at
10
C, a mixture of
bis(aziridinyl)urea 173 and 2-chloroethyl isocyanate 174 is formed, the former being
the major product [109].
Cl
Cl
NCN
O
N=C=O
Et
3
N
NH
+
+
+
Cl
O
173
174
171
2-Chloroethyl isocyanate 174 is the major product obtained when aziridine is allowed
to react with an equivalent amount of 1:1 triethylamine-phosgene complex 175 [108]
or 2:1 pyridine-phosgene complex 177 [109]. Aziridine carbamoyl chloride 176 was
postulated as a transient intermediate in this reaction. Attempts to trap this elusive
species as the triethylammonium or pyridinium salt have been unsuccessful [109].
Et
3
N
+
Et
3
NHCl
NH
COClCI
NCOCl
+
171
175
176
2 Cl
Cl
+
NCN
O
NH
N=C=O
171
177
174
Compounds containing both an isocyanate and a carbamoyl chloride group (for
example, 179) have been prepared by reacting monoalkyl a,o-diamines (for example,
178) with phosgene [111, 112].
COCl
2
R
NCO
R
NH
2
N
H
COCl
178
179
High dye-yield linking units having the N-alkyl-N-aryl carbamoyl chloride structure
