反应详情

A suspension of 25.0 g (0.055 mol) of [2-(2-nitro-5-trifluoromethylphenyl)-1-(4-methoxyphenyl)ethyl]propanedioic acid, dimethyl ester (see Example 4A) in 200 ml of methanol was treated with a cold suspension of 2.5 g of 5% palladium on charcoal in 50 ml of methanol (under nitrogen) and placed on the Parr apparatus at 58 lbs. of hydrogen. The theoretical amount of hydrogen was consumed in about 30 minutes and this mixture was then heated at 50°-55° C. for one hour to assure that all of the nitro compound had dissolved. The mixture was removed from the Parr and allowed to stand at room temperature overni-ght. The flask was heated to dissolve the crystallized product, and the hot solution was filtered through Celite (under nitrogen) and washed with hot methanol. The colorless filtrate was concentrated on a rotary evaporator to give 22.2 g of a nearly colorless solid. The latter was triturated with 100 ml of hexane and then with 50 ml of hexane. The solvent was decanted and the entrained solvent removed on a rotary evaporator to give 21.3 g of product, melting point 124°-127° C. A sample of this material, after crystallization from methanol, melted at 125°-127° C.

1. customThe theoretical amount of hydrogen was consumed in about 30 minutes
2. temperaturethis mixture was then heated at 50°-55° C. for one hour
3. dissolutionhad dissolved
4. customThe mixture was removed from the Parr
5. customto stand at room temperature
6. temperatureThe flask was heated
7. dissolutionto dissolve the crystallized product
8. filtrationthe hot solution was filtered through Celite (under nitrogen)
9. washwashed with hot methanol
10. concentrationThe colorless filtrate was concentrated on a rotary evaporator
11. customto give 22.2 g of a nearly colorless solid
12. customThe latter was triturated with 100 ml of hexane
13. customThe solvent was decanted
14. customthe entrained solvent removed on a rotary evaporator