4747-71-1Relevant articles and documents
Organosilicon synthesis of isocyanates: II. Synthesis of aliphatic, carbocyclic, and fatty-aromatic isocyanates
Lebedev,Lebedeva,Sheludyakov,Ovcharuk,Kovaleva,Ustinova
, p. 469 - 477 (2008/02/07)
Silylation of a series of aliphatic, carbocyclic, and fatty-aromatic amines gave the corresponding silyl derivatives whose yield depended on the electronic and steric structure of the substrate and the nature of the silylating agent. The yield of isocyanates obtained by phosgenation of the silyl derivatives under mild conditions decreased in going from aliphatic amines to benzylamines and rose as the length of the alkyl chain in fatty-aromatic amines extended. The most convenient procedure for the synthesis of low-boiling alkyl isocyanates was found to be based on the transformation of amines or ammonium salts into silyl or silyl silyl-carabamates, followed by pyrolysis of the latter in the presence of trichloro(phenyl)silane. Pleiades Publishing, Inc., 2006.
Alkylation of Nitrocyanamide. A New Synthesis of Isocyanates
Boyer, Joseph H.,Manimaran, Thanikavelu,Wolford, Lionel T.
, p. 2137 - 2140 (2007/10/02)
Thirteen alkyl halides (primary, secondary, and tertiary aliphatic including alicyclic, aralkyl, and heteroalkyl systems) and certain non-vicinal dihalides on treatment with silver nitrocyanamide are converted into the corresponding isocyanates (63-95percent).Intermediate alkylnitrocyanamides, spectroscopically detected, thermolysed (-20-80 deg C) to the expected isocyanates.In certain examples silver nitrocyanamide is generated in situ from sodium nitrocyanamide and silver nitrate.Silver nitrocyanamide does not react with cyclopropyl bromide, acetyl chloride, toluene-p-sulphonyl chloride, phenacyl bromide and 2-bromomethyldioxolane (27), and the ethylene acetal (28) of 1-bromo-4-iodopentacyclo-nonan-9-one.Silver nitrocyanamide reacts with 4,6-bis(bromomethyl)-3,7-dimethyl-1,5-diazabicyclo3.3.0)octane-2,8-dione (26), to give an intractable mixture.Vicinal dihalides give erratic results without detectable formation of vicinal di-isocyanates: unisolated 2-bromoethyl isocyanate (tentative assignment) has been detected in a product mixture from ethylene dibromide; an expected rearrangement during the reaction with 1,2-dibromocyclobutane, brought about the formation of 4-bromobut-3-enyl isocyanate isolated as ethyl 4-bromobut-3-enylcarbamate in low yield; and 1,2-dibromocyclohexane gives 2-bromocyclohexyl isocyanate isolated as ethyl N-(2-bromocyclohexyl)-carbamate in low yield.
