Phosgene → 2-Chloro-6-(4-isocyanatophenoxy)pyridine
Reaction equation
[C:1](Cl)(Cl)=[O:2].[Cl:5][C:6]1[N:11]=[C:10]([O:12][C:13]2[CH:18]=[CH:17][C:16]([NH2:19])=[CH:15][CH:14]=2)[CH:9]=[CH:8][CH:7]=1>C1(C)C=CC=CC=1>[Cl:5][C:6]1[N:11]=[C:10]([O:12][C:13]2[CH:18]=[CH:17][C:16]([N:19]=[C:1]=[O:2])=[CH:15][CH:14]=2)[CH:9]=[CH:8][CH:7]=1Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
A stream of phosgene was passed into 120 ml. of dry toluene maintained at a temperature of about 0° to about 5° C. until a weight of 13.4 grams (0.135 mole) had been absorbed. 4-((6-Chloro-2-pyridinyl)oxy)benzenamine (10.0 grams; 0.045 mole) in 100 ml. of dry toluene was then added to the stirred phosgene solution over a period of about 15 minutes while maintaining the reaction temperature within a range of about 2° to about 5° C. Following the completion of the addition, the reaction mixture was stirred for about 20 minutes and the reaction temperature then gradually raised as excess phosgene was purged with a stream of nitrogen. When a reaction temperature of about 85° C. was attained, the reaction mixture became clear. The toluene solvent was then substantially removed under reduced pressure and hexane added to the residue to give the desired 4-((6-chloro-2-pyridinyl)oxy)phenyl isocyanate product as a white crystalline product having a melting point of 96°-97° C.
Workup
- customhad been absorbed
- temperaturewhile maintaining the reaction temperature within a range of about 2° to about 5° C
- additionthe completion of the addition
- customwas purged with a stream of nitrogen
- customa reaction temperature of about 85° C.
- customThe toluene solvent was then substantially removed under reduced pressure and hexane
- additionadded to the residue
Sources & evidence
- ORD record
- ord-3f8ce0dae1934b2b8f8bb25b3f1250f6
- Source dataset
- uspto-grants-1977_01
- Patent number
- US04003734
Reaction notes
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