Dimethylformamide → Abacavir

Participants

Reaction Conditions

Reaction Steps

The title compound of Example 25 (0.91 g, 2.79 mmol) was dissolved in dry DMF (1 mL). Triethylorthoformate (10 mL) and ethane sulfonic acid (0.29 mL, 3.4 mmol) were added and the solution heated at 65° C. for 24 hours. The solution was evaporated to a syrup. The syrup was dissolved in 1N HCl (15 mL) and stirred for three hours. The pH was adjusted to 7 with 5N sodium hydroxide and the resulting mixture (oil formed) was extracted with i-propanol:chloroform/1:3 (3×100 mL). The combined organic layers were dried (MgSO4) and evaporated to a red glass (0.93 g). A solution of this glass in methanol (20 mL) was heated with cyclopropylamine (2 mL) in a Parr bomb at 70° C. for 18 hours. The resulting solution was evaporated to a dark glass which was adsorbed on silica gel. Elution with 7% methanol-ethylacetate gave title compound (148 mg, 19%) as white powder, after trituration with acetonitrile; 1H-NMR (DMSO-d6) identical with that of the title compound of Example 5.

Provenance & Evidence