Isonitrile prepn - from monosubstd alkyl or aryl formamide , triphenyl or tri-dimethylamino phosphine and tetrahalomethane

摘要

Isonitriles are prepd smoothly and in high yields by reacting monosubstd, aliphatic and aromatic formamides with triphenyl- or tri-(dimethylamino)-phosphine and a tetrahalomethane, pref. CCl4, pref. in solvents, esp. CH2Cl2, CHCl3, C2H4Cl2, acetonitrile or THF in presence of bases, e.g. NEt3, at 20-60 degrees C. Isonitrile yields are increased when using 20-30% excess phosphine deriv. Products are separated from reaction mixt. after distilling off solvent at weakly reduced press by extn with solvents, e.g. petroleum ether.