Water → Valdipromide

Participants

Reaction Conditions

Reaction Steps

In a 2-liter flask an 80% aqueous solution of 550 g of sulphuric acid was placed. While stirring, 110 g (0.66 mol) of tri-n-propylacetonitrile were added over a period of 20 minutes and at room-temperature. The temperature of the reaction medium rose to 80° C after which it was brought up to 105°-110° C for 6 hours. The solution was then cooled to 10° C and slowly poured into iced water (1000 g of purified water and 200 g of ice.) A pasty precipitate gradually formed as the solution was added to the iced water. As soon as the operation was finished, the mixture was stirred for 15 minutes and the precipitate centrifuged out and taken up twice in 350 g of ethyl ether. The ethereal solution was first washed twice with 200 g of water containing 10% of sodium bicarbonate and then twice with 250 g of water. The mixture was dried for 24 hours over 125 g of anhydrous sodium sulphate after which the sodium sulphate was centrifuged out. The ether was then eliminated by means of a rotatory evaporator which provided an oil which crystallized into fine needles which were left under vacuum until a constant weight was obtained. By this means, 113 g of crude tri-n-propylacetamide were obtained which represents a yield of 92.6%. The crude product was then dissolved by heating in 150 g of petroleum ether. After dissolution, 1.15 g of CECA WSL black was added and the mixture refluxed for 30 minutes. The black was then filtered off while the mixture was still hot. The filtrate was cooled to -15° C for 3 hours after which the precipitate which formed was centrifuged out and dried for 24 hours in a drying-oven at 40° C under 20 mm. Hg vacuum. In this way, 98.5 g of pure tri-n-propylacetamide were obtained which represents a yield in pure product of 87.1%. M.P. 69° C.

Provenance & Evidence