5-ethyl-1,3-oxazolidin-2-one

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In a three-necked flask equipped with a mechanical stirrer and reflux condenser, ethanol is acidified to a pH of 0.5-1.5 with 8 percent methanolic HCl. To the cooled alcohol is added acetaldehyde. The addition is so conducted that the temperature of the mixture stays under 40° C. The solution is stirred at room temperature for 2 hours after the completion of addition. The mole ratio of alcohol to acetaldehyde is about 1.5:1. 5-Ethyl-2-oxazolidinone (mole ratio of acetaldehyde to 2-oxazolidinone is 3:1) is added dropwise to the solution. The mixture is then stirred for 24 hours at 45° C. The mixture is then neutralized to a pH of 6.5-8 with a solution of sodium methoxide. After removing the unconsumed hemiacetal and alcohol under vacuum, the liquid 3-(1-ethoxyethyl)-5-ethyl-2-oxazolidinone is obtained. In a three-necked flask equipped with a mechanical stirrer reflux condenser The addition stays under 40° C after the completion of addition The mixture is then stirred for 24 hours at 45° C After removing the unconsumed hemiacetal and alcohol under vacuum

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 3-(1-Hydroxyethyl)-5-ethyl-2-oxazolidinone is prepared from 72 g (0.626 mole) of 5-ethyl-2-oxazolidinone by the procedure described in Example 1. A total of 96 g of 3-(1-hyroxyethyl)-5-ethyl-2-oxazolidinone is obtained (87 percent conversion). The 3-(1-hydroxyethyl)-5-ethyl-2-oxazolidinone is dehydrated in the hot tube filled with steel helices which is coated with a catalyst of NaHSO4. The dehydration is conducted at 260° C. under 40 mm Hg pressure. A dark red liquid (83 g) is collected which gives 64.6 g of N-vinyl-5-ethyl-2-oxazolidinone and 10.4 g of 5-ethyl-2-oxazolidinone upon fractionation. The yield is 87 percent based on 86 percent conversion of 5-ethyl-2-oxazolidinone. is conducted at 260° C. under 40 mm Hg pressure A dark red liquid (83 g) is collected which