Sulfuric Acid → 2,4'-Diphenylmethane diisocyanate

HRID 614918

Reaktionsgleichung

Reaktionsgleichung von HRID 614918
C(O[C:4]([CH:6](NC1C=CC=CC=1)[C:7]1[CH:12]=[CH:11][CH:10]=[CH:9][C:8]=1[NH:13][C:14](=[O:16])O)=O)C.S(=O)(=O)(O)O.C([O:31][C:32](=O)[NH:33][C:34]1[CH:39]=[CH:38]C=[CH:36][CH:35]=1)C>>[CH:11]1[CH:12]=[C:7]([CH2:6][C:4]2[CH:38]=[CH:39][C:34]([N:33]=[C:32]=[O:31])=[CH:35][CH:36]=2)[C:8]([N:13]=[C:14]=[O:16])=[CH:9][CH:10]=1

Komponenten

4

Edukt 3

HCID 1118Sulfuric AcidHCID 7591Ethyl N-phenylcarbamateHCID 54080679HCID 54080679, Verbindung2×

Produkt 1

HCID 625932,4'-Diphenylmethane diisocyanate

Reaktionsbedingungen

Temperatur
100 °C

Versuchsvorschrift

0.3 g. of an ethyl ester of 2-[(ethoxycarbonyl)-phenylaminomethyl]phenylcarbamic acid (N-benzyl compound), prepared as in Example 1, along with 1.0 g. of 96.4 weight percent concentrated sulfuric acid was charged to a 300 ml reaction flask. The mixture was heated to 100° C. on a constant temperature bath for 60 minutes. High speed liquid chromatographic analysis showed conversion of the ethyl ester of 2-[(ethoxycarbonyl)phenylaminomethyl]phenylcarbamic acid to the diethyl ester of 2,4'-methylenebis(phenylcarbamic) acid and higher homologs to be 99+ percent with minor amounts of ethylphenylcarbamate. After acid extraction with water, the resulting 2,4'-methylenebis(phenylcarbamic) acid, diethyl ester (diurethane) was subjected to thermal decomposition by the method described in U.S. Pat. No. 3,962,302 to produce the diphenylmethane-2,4'-diisocyanate in good yield.

Aufarbeitung

  1. extractionAfter acid extraction with water

Quellen und Nachweise

ORD-Eintrag
ord-f77e65ede304476c85a3b460852e6e18
Quelldatensatz
uspto-grants-1979_03
Patentnummer
US04146727

Verknüpfte Notizen

Wird geladen…