N-[acetamido(phenyl)methyl]acetamide

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

Procedure: A stirred solution-suspension of 11.8 g (0.05 mol) of 5-(3-methyl-2-octyl)-resorcinol (4) (65% dl-erythro and 35% dl-threo) and 10.7 g (0.052 mol) of N,N'-benzylidenebisacetamide (2) in 60 ml of methylene chloride cooled to 2° in an ice bath was treated dropwise with 4.9 ml (0.05 mol) of phosphorus oxychloride over a period of 5 to 10 minutes. The stirring was continued in the melting ice bath. A clear solution formed after 2 to 2.5 hours and precipitation of produce occurred after 3 to 3.5 hours. After being stirred at room temperature overnight, the reaction mixture was treated with water (40 ml) and more methylene chloride (70 ml). After the slight exothermic reaction was complete, the organic layer containing suspended product was separated and washed successively with water (2 × 100 ml), 5% sodium bicarbonate (100 ml), and water (100 ml). Filtration of the organic layer gave 5.00 g of colorless crystalline powder, mp 204-208°. Concentration of the filtrate and cooling gave 2.58 g, mp 196-199°, as a second crop (7.58 g = 40% yield). Concentration to dryness left 10.8 g of an amorphous glassy solid which could not be crystallized. Its pmr spectrum was similar to that of the crystalline fraction, suggesting it consisted of a mixture of stereoisomers. Recrystallization from acetonitrile of a sample of the 7.58 g to constant mp gave pure 2-(α-acetylaminobenzyl)-5-(3-methyl-2-octyl)-resorcinol (6) mp 209°-210° (probably a single stereo-isomer); ir (Nujol) 3400 (νNH or OH), 3200 (broad, ν bonded OH), and 1610 cm-1 (νC=O); pmr (DMSO-d6) δ 9.0 -9.8 (m, 2H, OH), 7.98 (d, 1H, J = 9 Hz, NH), 7.0 - 7.5 (m, 5H, C6H5), 6.64 (d, 1H, J = 9 Hz, Ar2CHNH), 6.18 (s, 2H, C6H2) and 1.92 ppm (s, 3H, CH3CO); m/e (M+) 383. cooled to 2° in an ice bath A clear solution formed after 2 to 2.5 hours precipitation of produce After the slight exothermic reaction the organic layer containing was separated washed successively with water (2 × 100 ml), 5% sodium bicarbonate (100 ml), and water (100 ml) Filtration of the organic layer