Water → 4,5-Dihydro-7-[3-(trifluoromethyl)phenyl]pyrazolo[1,5-a]pyrimidine-3-carboxylic acid, ethyl ester

HRID 2050507Notes

Reaction equation

HRID 2050507 reaction equation
[F:1][C:2]([F:24])([F:23])[C:3]1[CH:4]=[C:5]([C:9]2[N:14]3[N:15]=[CH:16][C:17]([C:18]([O:20][CH2:21][CH3:22])=[O:19])=[C:13]3[N:12]=[CH:11][CH:10]=2)[CH:6]=[CH:7][CH:8]=1.C([BH3-])#N.[Na+].O>C(O)(=O)C>[F:23][C:2]([F:1])([F:24])[C:3]1[CH:4]=[C:5]([C:9]2[N:14]3[N:15]=[CH:16][C:17]([C:18]([O:20][CH2:21][CH3:22])=[O:19])=[C:13]3[NH:12][CH2:11][CH:10]=2)[CH:6]=[CH:7][CH:8]=1

Participants

5

Reactant 3

HCID 962WaterHCID 5003444Sodium cyanoborohydrideHCID 111984377-[3-(Trifluoromethyl)phenyl]pyrazolo[1,5-a]pyrimidine-3-carboxylic acid ethyl ester

Product 1

HCID 1363369154,5-Dihydro-7-[3-(trifluoromethyl)phenyl]pyrazolo[1,5-a]pyrimidine-3-carboxylic acid, ethyl ester

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

To a 20.0 g amount of 7-(3-(trifluoromethyl)-phenyl)pyrazolo(1,5-a)pyrimidine-3-carboxylic acid, ethyl ester (U.S. Pat. No. 4,178,449, Example 16) stirred in 100 ml of glacial acetic acid and cooled in a water bath is added portionwise 10.0 g of sodium cyanoborohydride under nitrogen. The mixture is stirred at room temperature for 3 hours. Evaporation of the mixture in vacuo gives an oil which solidifies on treatment with water. This solid is collected by filtration and is then stirred with a saturated solution of sodium bicarbonate, then is filtered, washed with water and dried in vacuo to give a white solid. Recrystallization from isopropyl alcohol gives 18.2 g of the desired product, mp 108-110° C.

Workup

  1. temperaturecooled in a water bath
  2. customEvaporation of the mixture in vacuo
  3. customgives an oil which
  4. filtrationThis solid is collected by filtration
  5. stirringis then stirred with a saturated solution of sodium bicarbonate
  6. filtrationis filtered
  7. washwashed with water
  8. customdried in vacuo
  9. customto give a white solid
  10. customRecrystallization from isopropyl alcohol

Sources & evidence

ORD record
ord-c3bb5166088147efba34ff31637152c2
Source dataset
uspto-grants-1991_05
Patent number
US05013737

Reaction notes

Loading…