Chloroform methanol → HCID 54174272, compound

Participants

Reaction Steps

To produce diazomethane, 1.0 g (10 mmol) N-methyl-N-nitrosourea was added portionwise with cooling to 20 ml diethyl ether to which 7 ml of 40% KOH had been added to form a lower layer, in such a way that the reaction temperature did not exceed +5° C. 30 min after the last addition the yellow organic phase was separated off and allowed to stand for 3 h over a little solid KOH. Enough of the ethereal solution of diazomethane thus obtained was added at room temperature with stirring during a period of 15 min to a solution of 500 mg (1.6 mmol) GMF carboxylic acid (formula 4, product of Example 4) in 18 ml methanol and 2 ml water for the yellow colour just to remain and no further evolution of gas to be observed. After a further 15 min stirring the reaction was complete (TLC monitoring with mobile solvent chloroform/methanol (2:1), Rf (educt)=0, Rf (product)= 0.41), whereupon the solvent was removed under vacuum and the crude product was purified by elution from a silica gel column (3×20 cm) with chloroform/methanol (2:1). Concentration of the fractions containing the product gave 440 mg (84%) of colourless syrup with [α]D20 =+113° (c=0.8, methanol), which gradually crystallised on scratching; m.p. 72° C.

Provenance & Evidence