Hydrochloric Acid → 4-(5-Trifluoromethylpyrid-2-yloxy)phenylisocyanate

HRID 652058Notes

Reaction equation

[F:1][C:2]([F:18])([F:17])[C:3]1[CH:4]=[CH:5][C:6]([O:9][C:10]2[CH:16]=[CH:15][C:13]([NH2:14])=[CH:12][CH:11]=2)=[N:7][CH:8]=1.Cl.[C:20](Cl)(Cl)=[O:21]>ClC1C=CC=CC=1>[F:18][C:2]([F:1])([F:17])[C:3]1[CH:4]=[CH:5][C:6]([O:9][C:10]2[CH:11]=[CH:12][C:13]([N:14]=[C:20]=[O:21])=[CH:15][CH:16]=2)=[N:7][CH:8]=1

Participants

Conditions

Temperature: -20 °C

Procedure

20.3 g (0.08 mol) of 4-(5-trifluoromethylpyrid-2-yloxy)aniline are dissolved in 200 ml of dry chlorobenzene. This solution is cooled to -20° C. and rapidly added a solution of 3.7 g of gaseous HCl in 80 ml of dry chlorobenzene. The resultant crystalline slurry is cooled to -30° C. and a strong flow of about 40 g of phosgene is introduced over 1 hour. The addition of phosgene is then discontinued and the reaction mixture is stirred for 1 hour at 20° C. and subsequently for 1 hour in an oil bath at 110° C. A clear solution forms which is then cooled in a stream of nitrogen and, with stirring, excess phosgene is expelled with nitrogen. First the chlorobenzene is distilled off under normal pressure and then the isocyanate is distilled off under a high vaccum. Boiling point 105°-107° C./0.03 mbar; yield>90%.

Workup

temperatureThe resultant crystalline slurry is cooled to -30° C.
temperatureA clear solution forms which is then cooled in a stream of nitrogen
stirringwith stirring
distillationFirst the chlorobenzene is distilled off under normal pressure
distillationthe isocyanate is distilled off under a high vaccum

Sources & evidence

ORD record: ord-d050fb09f5834925a1fa75e709fa8711
Source dataset: uspto-grants-1987_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04670441

Reaction notes

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