Methanol → (R)-N-[9-(2,3-Dihydro-2-furanyl)-9H-Purin-6-yl]-2,2-dimethylpropanamide

関与物質

反応条件

反応手順

To a suspension of the product of Step C (196 g, 0.97 mole), 4-dimethylaminopyridine (5.9 g, 0.048 mole) in dry pyridine (970 mL) at 26° C. was added dropwise over 1 hr trimethylacetylchloride (145 mL, 142.1 g, 1.18 mole, 1.2 equiv.). A slight 3° C. exotherm was noted. The reaction mixture was then heated to 55° C. for 4 hr becoming a pale yellow-orange solution. Analysis by TLC (methylene chloride:methanol (90:10), Rf (product) 0.75) showed the reaction was complete. The reaction solution was cooled to 25° C. and methanol (40 mL) was slowly added. The reaction solution was then stirred for 30 min, then concentrated in vacuo to a thick orange syrup. The residue was dissolved in methylene chloride (1.5 liters) and washed with 0.5N sodium bisulfate (3×500 mL), 1N sodium bisulfate (2×500 mL), then brine (1×500 mL). All aqueous washes were combined and extracted with methylene chloride (1×500 mL). All methylene chloride extracts were combined and dried over anhydrous sodium sulfate, then filtered and concentrated in vacuo to a light orange oil. The oil was suspended in toluene (200 mL) and concentrated in vacuo. The product solidified to a pale yellow solid weighing 262 g for a yield of 94%.

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