反应详情

温度

40 °C

To 7869 kg of a recovered acetal solution comprising 74.4 wt % dimethylacetal, 13.8 wt % methanol, 7.5 wt % acetaldehyde, 3.3 wt % methyl acetate and 1 wt % water obtained in the water separation step described below and 144 kg of methanol obtained in the N-vinylacetamide concentration step described below, there was added an additional 15 kg of methanol, and then 212 kg of recycled solution comprising 11.0 wt % acetamide, 54.4 wt % N-vinylacetamide, 32.2 wt % N-(1-methoxyethyl)acetamide and 2.4 wt % of other components obtained by the filtrate recovery step described below, 239 kg of acetamide and 165 kg of acetaldehyde were added thereto and thoroughly mixed to prepare a reaction starting solution. The molar ratio of the N-vinylacetamide and the N-(1-methoxyethyl)acetamide, acetamide, acetal, acetaldehyde, water and methanol in the mixture was 1:0.28:3.14:46.4:12.3:3.64:27.8. In terms of "moieties" the proportion was "amide":"ethylidene":"methoxy":"water"=1:13.2:26.6:3.5. Of this starting material, 450 L was fed each hour through the top of a reactor filled with 150 L of the strongly acidic ion-exchange resin "Dowex MSC-1" (registered trademark). Warm water at 40° C. was poured over the jacket of the reactor to maintain a reaction temperature of 40° C. The reaction results were calculated based on quantitative analysis by gas chromatography, after neutralization of the reaction solution obtained through the outlet at the bottom of the reactor. Based on the reaction results, the N-(1-methoxyethyl)acetamide yield (with respect to acetamide+N-(1-methoxyethyl)acetamide+N-vinylacetamide) was 88.0%, and the ethylidene bisacetamide yield as a reaction by-product (calculated on the same standard as the N-(1-methoxyethyl)acetamide yield) was 4.0%.

1. customobtained by the filtrate recovery step
2. additionwere added
3. additionthoroughly mixed
4. customto prepare a reaction
5. waitOf this starting material, 450 L was fed each hour through the top of a reactor
6. additionfilled with 150 L of the strongly acidic ion-exchange resin "Dowex MSC-1" (registered trademark)
7. customThe reaction results
8. customafter neutralization of the reaction solution obtained through the outlet at the bottom of the reactor
9. customresults