Acetone → Benzamide

Temperature

0 °C

81.3 g of 2-methoxy-4-acetamino-5-methylsulphinylbenzoic acid (0.30 mole), 600 ml of acetone, 120 ml of water and 41.7 ml of triethylamine with a density of 0.726 (0.30 mole) are placed in a 1 liter flask fitted with an agitator, a thermometer, a condenser and a dropping funnel. The mixture is cooled to 0° C. and 40.8 g of isobutyl chloroformate (0.30 mole) is poured in drop by drop. It is agitated for 30 minutes with the cooling bath removed, cooled to 0° C. again and 54.6 g of 1-cyclohexyl-2-aminomethyl-pyrrolidine (0.30 mole) is poured in drop by drop. The mixture is reacted for 1 hour at room temperature with agitation, and left to stand. The solution is evaporated to dryness. A paste is obtained and is dissolved in 200 ml of soda and 400 ml of water. It is heated to reflux for 2 hours, and 50 ml of a mixture distilling over at low temperature is distilled off then put back under reflux. The reaction medium is left to stand, then the suspension is extracted four times with 200 ml of methylene chloride. The organic phase is washed twice with 300 ml of 10% hydrochloric acid, the aqueous phase is filtered with carbon black and the filtrate is made alkaline with 300 ml of 40% soda. The suspension is extracted 3 times, each time with 300 ml of methylene chloride. The organic solution is washed with water and dried over magnesium sulphate. The solution is filtered and evaporated to dryness. 42.5 g (36%) of benzamide is obtained; this does not crystallise.

1. customfitted with an agitator
2. customremoved
3. temperaturecooled to 0° C. again
4. customThe mixture is reacted for 1 hour at room temperature with agitation
5. waitleft
6. customThe solution is evaporated to dryness
7. customA paste is obtained
8. temperatureIt is heated
9. temperatureto reflux for 2 hours
10. distillation50 ml of a mixture distilling over at low temperature
11. distillationis distilled off
12. temperatureunder reflux
13. waitThe reaction medium is left
14. extractionthe suspension is extracted four times with 200 ml of methylene chloride
15. washThe organic phase is washed twice with 300 ml of 10% hydrochloric acid
16. filtrationthe aqueous phase is filtered with carbon black
17. extractionThe suspension is extracted 3 times
18. washThe organic solution is washed with water
19. dry with materialdried over magnesium sulphate
20. filtrationThe solution is filtered
21. customevaporated to dryness

ORD record

ord-328b7b149f8e4952b6891c0eddd2ccfd

Source dataset

uspto-grants-1987_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04673686