Benzamide → N-[(3S,4R)-3-Hydroxy-2,2-dimethyl-6-(trifluoromethoxy)-chroman-4-yl]-6-methyl-2-nitrobenzamide

2-Methyl-6-nitrobenzoic acid (1.81 g, 10 mmol) was converted to the corresponding acid chloride by refluxing in benzene (30 mL) with thionyl chloride (1.66 g, 14 mmol) for 0.5 hours. The crude mixture was concentrated in vacuo and diluted with dichloromethane (10 mL). This solution was added to a cooled solution of (3S,4R)-4-amino-2,2-dimethyl-6-(trifluoromethoxy)-chroman-3-ol (2.75 g, 10 mmol), triethylamine (1.39 mL, 10 mmol) and dichloromethane (25 mL). The crude benzamide was worked-up in a method similar to that in Example 1 and chromatographed (1:1 hexanes/ethyl acetate) to afford 2.5 g (62%) of a white solid: m.p. 204°-206° C.; 1H NMR (CDCl3): δ 8.02 (d, 1H), 7.58 (d, 1H), 7.48 (t, 1H), 7.20 (s, 1H), 7.04 (d, 1H), 6.82 (d, 1 H), 6.06 (d, 1H), 3.80 (t, 1H), 3.70 (br s, 1H), 2.56 (s, 3H), 1.52 (s, 3H), 1.31 (s, 3H).

1. concentrationThe crude mixture was concentrated in vacuo
2. additiondiluted with dichloromethane (10 mL)
3. customchromatographed (1:1 hexanes/ethyl acetate)

ORDレコード

ord-d2add3c02dae4436b92cc53ece9babf4

出典データセット

uspto-grants-1993_07

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US05225566