Reaktion #452145

Reaktionsgleichung

diethyl 4-(4-benzofurazanyl)-2-formyl-1,4-dihydro-6-(trifluoromethyl)-3,5-pyridinedicarboxylate

sodium borohydride

hydrochloric acid

→

title compound

Ausbeute 45.3%

Diethyl 4-(4-benzofurazanyl)-1,4-dihydro-2-(hydroxymethyl)-6-trifluoromethyl-3,5-pyridinedicarboxylate

Ausbeute 45.3%

Lösungsmittel

ethanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   Einengenthe mixture concentrated in vacuo at room temperature
2. 2
   workup.DISSOLUTIONThe resulting yellow oil was dissolved in ether (50 ml)
3. 3
   workup.ADDITIONsaturated aqueous sodium bicarbonate was added to pH9
4. 4
   SonstigeThe organic solution was separated
5. 5
   Waschenwashed with saturated aqueous sodium bicarbonate solution, water, brine
6. 6
   Trocknendried (MgSO4)
7. 7
   SonstigeEvaporation of the solvent
8. 8
   workup.WAITleft a yellow oil which
9. 9
   Sonstigewas crystallised from 2-propanol

Vorschrift

A solution of diethyl 4-(4-benzofurazanyl)-2-formyl-1,4-dihydro-6-(trifluoromethyl)-3,5-pyridinedicarboxylate (1.1 g; 2.5 mmoles) in dry ethanol (90 ml) was cooled to 0° and sodium borohydride (0.14 g; 3.7 mmoles) was added portionwise over 3 minutes. After 10 minutes, 10% aqueous hydrochloric acid was added dropwise to pH3, and the mixture concentrated in vacuo at room temperature. The resulting yellow oil was dissolved in ether (50 ml) and saturated aqueous sodium bicarbonate was added to pH9. The organic solution was separated, washed with saturated aqueous sodium bicarbonate solution, water, brine and dried (MgSO4). Evaporation of the solvent left a yellow oil which was crystallised from 2-propanol to give the title compound (0.5 g) mp 110°-11°.

Quelle