AROMATIC BISMALEIMIDO COMPOUNDS AND PROCESS FOR THEIR PREPARATION.

摘要

Aromatic bismaleimides of formula (I) are new: where X is one of the groups (III) to (VI); R1 to R4 are H or methyl: (a) reaction of a diol of fromula HO-X-OH with 1.5-4.0 moles of m-dinitrobenzene in a polar aprotic solvent in the presence of 1.5-3 moles of an alkali metal (bi)carbonate, followed by hydrogenation over Pd in an organic solvent at 20-100 deg. C gives a diamine of formula (II): (b) the diamine (II) is reacted with 2-5 moles of maleic anhydride in an organic solvent (pref. an aliphatic ketone) at 0-120 deg. C to give a bismaleamic acid, which is cyclised with acetic anhydride (at least 2 moles) in an organic solvent in the presnece of an alkali acetate or tertiary amine and of a catalyst (0.05-1.1 moles= which is a phosphate, acetate, oxide, sulphate or carbonate of an alkaline earth metal, Fe(II), Fe(III), Ni(II), Mn(II), Mn(III), Cu(I), Cu(II), Co(II) or Co(III) (esp. Ni(OAc)2, Co(OAc)2 or MgO) at 20-80 deg. C.