Dimethylformamide → 2-Amino-5-methylbenzamide

To a stirred solution of 5-methyl-2-nitrobenzoic acid (25.4 g) in THF (150 ml) was added oxalyl chloride (13.5 ml) and DMF (0.1 ml) dropwise and the mixture was stirred at room temperature for 14 hours and concentrated to dryness. To an ice-cooled, stirred 25% aqueous solution of ammonia (150 ml) was added the resulting acid chloride dropwise and the mixture was stirred at the same temperature for 1 hour. The white precipitates were collected by filtration, washed with water, and dried in vacuo. A suspension of the white precipitates and 10% Pd/C (2.4 g) in a mixture of THF (200 ml) and methanol (150 ml) was stirred under hydrogen atmosphere at room temperature for 4 hours. After removal of insoluble materials by filtration, the filtrate was concentrated to dryness. Recrystallization of the resultant crystalline residue from ethyl acetate-hexane afforded colorless crystals (18.7 g, 89%), m.p. 178°-180° C.

1. concentrationconcentrated to dryness
2. temperatureTo an ice-cooled
3. stirringstirred 25% aqueous solution of ammonia (150 ml)
4. additionwas added the resulting acid chloride dropwise
5. stirringthe mixture was stirred at the same temperature for 1 hour
6. customThe white precipitates
7. filtrationwere collected by filtration
8. washwashed with water
9. customdried in vacuo
10. additionA suspension of the
11. customwhite precipitates
12. addition10% Pd/C (2.4 g) in a mixture of THF (200 ml) and methanol (150 ml)
13. stirringwas stirred under hydrogen atmosphere at room temperature for 4 hours
14. customAfter removal of insoluble materials
15. filtrationby filtration
16. concentrationthe filtrate was concentrated to dryness
17. customRecrystallization of the resultant crystalline residue from ethyl acetate-hexane afforded colorless crystals (18.7 g, 89%), m.p. 178°-180° C.

ORDレコード

ord-5ad1512109eb4bbb95d6ba8e7a9ccfea

出典データセット

uspto-grants-1995_02

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US05389641