Water → 4-Isocyanatobenzene-1-thiol

Temperature

90 °C

To a suspension of 4-(t-butylmercapto)nitrobenzene (52.8 g., 0.25 mol) and iron powder (150 g.) in 1 l. of water there was added 1 ml. of acetic acid. The reaction mixture was stirred 18 hours at 90° C. and filtered. Both the residue and filtrate were extracted several times with methylene dichloride, and the combined dried methylene dichloride extracts were concentrated at reduced pressure to give 18.2 g. of a brown oil. This is a 40% weight yield of 4-(t-butylmercapto)aniline. To this oil in 100 ml. of benzene there was then added dropwise 158 g. of a 12.5% benzene solution of phosgene (0.2 mol) with cooling. The reaction mixture was stirred for 1 hour at 10° C., overnight at room temperature and then at reflux temperature for 7 hours. After standing overnight the reaction mixture was filtered, the filtrate concentrated at reduced pressure, then vacuum-distilled. Two product fractions were collected as

1. filtrationfiltered
2. extractionBoth the residue and filtrate were extracted several times with methylene dichloride
3. concentrationwere concentrated at reduced pressure
4. customto give 18.2 g
5. stirringThe reaction mixture was stirred for 1 hour at 10° C., overnight at room temperature
6. temperatureat reflux temperature for 7 hours
7. waitAfter standing overnight
8. filtrationthe reaction mixture was filtered
9. concentrationthe filtrate concentrated at reduced pressure
10. distillationvacuum-distilled
11. customTwo product fractions were collected as

ORD record

ord-cf72c76e56fb436d9add06f9f7dfe9d2

Source dataset

uspto-grants-1978_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04075345