Hydrochloric Acid → 4-Aminopyrazolo[1,5-a]pyridine-2-carboxylic acid

HRID 2039783노트

반응식

HRID 2039783 반응식
C[O:2][C:3]([C:5]1[C:14](C(OC)=O)=[C:8]2[C:9]([NH2:13])=[CH:10][CH:11]=[CH:12][N:7]2[N:6]=1)=[O:4].[OH-].[Na+].Cl>OS(O)(=O)=O>[NH2:13][C:9]1[C:8]2[N:7]([N:6]=[C:5]([C:3]([OH:4])=[O:2])[CH:14]=2)[CH:12]=[CH:11][CH:10]=1

참가 물질

5

반응물 3

HCID 313Hydrochloric AcidHCID 14798Sodium HydroxideHCID 595389664-Aminopyrazolo[1,5-a]pyridine-2,3-dicarboxylic acid dimethyl ester

생성물 1

HCID 686499974-Aminopyrazolo[1,5-a]pyridine-2-carboxylic acid

시약·촉매·용매 1

HCID 1118Sulfuric Acid용매

반응 조건

온도
80 °C

실험 절차

50% Aqueous H2SO4 (60 mL) is added to 4-Aminopyrazolo[1,5-a]pyridine-2,3-dicarboxylic acid dimethyl ester (1.47 g, 5.90 mmol) under air. The mixture is warmed to 80° C. After 6.5 h, the solution is cooled to 0° C. and then neutralized with 10 N aq. NaOH. The resulting slurry is acidified to pH 3 with 1 M aq. HCl. The volatiles are removed under reduced pressure. The residue is washed with 30% EtOH in CH2Cl2. The volatiles are removed under reduced pressure to afford 4-aminopyrazolo[1,5-a]pyridine-2-carboxylic acid in Na2SO4. LC-MS m/z (M+H+): 178.01. A solution of conc. H2SO4 (6.0 mL) and ethanol (120 mL) is added to the crude 4-aminopyrazolo[1,5-a]pyridine-2-carboxylic acid. The mixture is warmed to 75° C. for 3.5 h. After cooling to rt, the mixture is made basic with dropwise addition of sat. aq. NaHCO3. The volatiles are removed under reduced pressure. The aqueous mixture is filtered (EtOAc rinse). The aqueous solution is extracted with EtOAc (3×250 mL). The combined organics are dried over Na2SO4, filtered, and concentrated to afford the title compound as dark brown solid. LC-MS m/z (M+Na+): 228.03.

후처리

  1. temperaturethe solution is cooled to 0° C.
  2. customThe volatiles are removed under reduced pressure
  3. washThe residue is washed with 30% EtOH in CH2Cl2
  4. customThe volatiles are removed under reduced pressure

출처 및 근거

ORD 기록
ord-948998633cff4ad4a91cf0bcbaef4522
출처 데이터셋
uspto-grants-2013_11
특허 번호
US08580812B2

반응 노트

불러오는 중…