N-(1-methoxyethyl)acetamide → N-Vinylacetamide

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

The pyrolysis apparatus consisted of a 250 ml 3-neck flask for vaporization immersed in an oil bath at 150° (fitted with a nitrogen inlet, a dropping funnel, a magnetic stirrer and an outlet to the pyrolysis tube); a quartz (20 inch×1inch) pyrolysis tube (packed with stainless steel shavings and heated to 580° C. with a heating tape); and two traps, the first in ice-water and the second in CO2 acetone. The internal pressure was 7-10 mm and the internal nitrogen flow was ~1 liter/min. (~10 ml/min. at 1 atm). The N-α-methoxy-ethyl acetamide was added to the vaporization flask in small (25 grams) portions to prevent the disproportionation that sometime occurred with larger quantities being heated longer times. The N-α-methoxy-ethyl acetamide evapoarated and passed through the pyrolysis tube at ~1 gram/min. In a typical run 103 grams of N-α-methoxy-ethyl acetamide gave 3.5 grams of residue and 72 grams of N-vinyl acetamide. The residues in the two traps were combined, diluted with 75 ml of MeOH, treated with 1 gram of activated charcoal. The methanol was evaporated and the residue distilled 79°-80° at 1.7 mm to give 71 grams of white crystals (95%).

Herkunft & Nachweise