Nicotinic Acid → HCID 13388141, Verbindung

To a mixture of 107 g of nicotinic acid and 315 ml of nitrobenzene were added dropwise whilst stirring 107 g of thionyl chloride, the mixture was warmed for one hour at a temperature of 160°-180° C. The reaction mixture was allowed to cool, then 35 g of 2-methylpyrazolo[1,5-a]pyridine was introduced in one portion, and the mixture was heated to 140°-160° C. for 2 hours, and poured into 1 l of ice water. Next, 50 ml of concentrated hydrochloric acid were added. This solution was extracted twice with 500 ml of benzene. After neutralizing with potassium carbonate, the aqueous layer was extracted with chloroform, the extract was dried with anhydrous Na2SO4 and after removal of the chloroform, the residue was chromatographed over SiO2 employing CH2Cl2 --AcOEt (3:2) mixture as eluent. The eluate was evaporated to dryness in vacuo and the residue was recrystallized (EtOH-Hexane); yield 30 g (46%), mp 89°-90° C.

1. additionwere added dropwise
2. temperaturethe mixture was warmed for one hour at a temperature of 160°-180° C
3. temperatureto cool
4. temperaturethe mixture was heated to 140°-160° C. for 2 hours
5. extractionThis solution was extracted twice with 500 ml of benzene
6. extractionthe aqueous layer was extracted with chloroform
7. dry with materialthe extract was dried with anhydrous Na2SO4
8. customafter removal of the chloroform
9. customthe residue was chromatographed over SiO2
10. customThe eluate was evaporated to dryness in vacuo
11. customthe residue was recrystallized (EtOH-Hexane)

ORD-Eintrag

ord-b9ea00f2bc7e46dfae259c02092f33b5

Quelldatensatz

uspto-grants-1985_12

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US04559402