To obtain a bismaleimide useful as a heat-resistant cross-linking agent or a heat-resistant resin monomer in an extremely high addition rate by subjecting a bismeleiamic acid to a dehydrative ring-closing reaction in the presence of a Lewis acid.
This method for producing a bismaleimide of formula II comprises subjecting (A) a bismaleiamic acid of formula I [L is a (substituted) 1-6C alkylene, an arylene, diphenylene or the like; R1, R2, R1', R2' are each H, a halogen or the like] to a dehydrative ring-closing reaction in the presence of (B) hexamethyldisilazane and a Lewis acid (preferably, a zinc halide, an aluminum halide or the like) in an organic solvent (preferably, N,N- dimethylformamide, dimethylsulfoxide or the like). The component A and the component B are preferably used in a molar ratio of 1:(2-2.1).
PAIDI IERA REDDIE
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