تفاعل #41162

معادلة التفاعل

5-Chloro-1-(tetrahydro-pyran-4-yl)-1H-pyrazole-4-carboxylic acid ethyl ester

Lithium hydroxide

water

→

5-chloro-1-(tetrahydro-pyran-4-yl)-1H-pyrazole-4-carboxylic acid

المردود 99.1%

المذيبات

methanol

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةAfter cooling to room temperature
2. 2
   تركيزthe mixture was concentrated
3. 3
   أخرىto remove the methanol
4. 4
   workup.ADDITIONTetrahydrofuran was added to the residue
5. 5
   أخرىremoved in vacuo
6. 6
   أخرىremoval of the methanol
7. 7
   workup.ADDITIONThe aqueous residue was treated with 6N HCl (1.88 mL)
8. 8
   أخرىresulting in the precipitation of a thick milky solid
9. 9
   ترشيحThe solid was collected by filtration
10. 10
    غسيلwashed with water
11. 11
    أخرىdried under high vacuum
12. 12
    درجة الحرارةwith heat

الإجراء التجريبي

5-Chloro-1-(tetrahydro-pyran-4-yl)-1H-pyrazole-4-carboxylic acid ethyl ester (2.194 g (98%), 8.31 mmol) was dissolved in methanol (12.5 mL). Lithium hydroxide (0.274 g, 11.44 mmol) and water (12.5 mL) were added and the mixture was heated at 80° C. for 1 hour. After cooling to room temperature, the mixture was concentrated to remove the methanol. Tetrahydrofuran was added to the residue and removed in vacuo to ensure complete removal of the methanol. The aqueous residue was treated with 6N HCl (1.88 mL) resulting in the precipitation of a thick milky solid. The solid was collected by filtration, washed with water and dried under high vacuum with heat to give 5-chloro-1-(tetrahydro-pyran-4-yl)-1H-pyrazole-4-carboxylic acid (1.900 g, 99%). Mass spectrum: m/z: 231.30 (M+H).

المصدر