| 摘要 |
1,155,104. Aromatic nitrite carbonates and the preparation of isocyanates therefrom. SINCLAIR RESEARCH Inc. 21 Oct., 1966 [22 Oct., 1965 (4)], No. 47150/66. Heading C2C. Compounds of the formula wherein R is an aromatic hydrocarbon radical of 1 to 3 aromatic rings, unsubstituted or substituted by non-interfering groups, and n is 0 or 1-3, provided (i) that the aromatic ring is substituted when n=0 and R has one aromatic ring, (ii) that the aromatic ring is substituted by non-interfering groups and/or the nitrile carbonate groups are in ortho or meta relationship when R has one aromatic ring and n= 1, (iii) that when n = 0 the nitrile carbonate group is attached to an aromatic ring of R, and (iv) that when n = 1 or more at least two nitrile carbonate groups are attached to aromatic rings of R, may be prepared by reacting an aromatic mono- or poly-hydroxamic acid of the formula with phosgene. The reaction is conducted in the liquid phase, optionally in the presence of a solvent, at a temperature below the decomposition temperature of the desired nitrile carbonate. Aromatic isocyanates are obtained by subjecting a compound of the formula to thermal decomposition, wherein R<SP>1 </SP>is an aromatic hydrocarbon radical of 1 to 3 aromatic rings, unsubstituted or substituted by non- interfering groups, and m=0 or 1-3. The decomposition is effected by heating, preferably at 50-200‹ C., and advantageously in an inert solvent. |
