Reaction #1687631

Reaction equation

methanol ether

P2O5

77

N-Methoxycarbonylmethyl-nicotinamide

sodium carbonate

→

5-Methoxy-2-(3-pyridyl)-oxazole

Solvents

water

chloroform

chloroform

Conditions

Workup

1. 1
   FiltrationThe mixture was filtered
2. 2
   Temperatureafter cooling
3. 3
   OtherThe filtrate was evaporated in vacuo
4. 4
   Otherleaving a red oil
5. 5
   ExtractionExtraction with 3×200 ml of dichloromethane
6. 6
   Dryingdrying of the combined organic phases over magnesium sulphate, and removal of the solvent in vacuo
7. 7
   Othergave a red oil which
8. 8
   Othergiving a colorless oil, 78

Procedure

A solution of 19.0 g (0.100 mol) of 77 in 300 ml of dry chloroform was refluxed under vigorous stirring with 40 g of P2O5 for 24 h. The mixture was filtered after cooling. The filtrate was evaporated in vacuo leaving a red oil. The precipitate was dissolved in water at 0°-5° C. and the aqueous solution made basic with sodium carbonate. Extraction with 3×200 ml of dichloromethane, drying of the combined organic phases over magnesium sulphate, and removal of the solvent in vacuo gave a red oil which was combined with the above mentioned oil obtained from the chloroform phase. The oil was applied to a silica gel column (eluent; methanol/ether=1/19) giving a colorless oil, 78. Yield: 5.9 g (0.034 mol, 34%).

Source