Pivaloyl chloride → N-(4-Oxo-4,7-dihydro-1H-pyrrolo[2,3-d]pyrimidin-2-yl)pivalamide

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Reaction Steps

A solution of 2-amino-3,7-dihydro-pyrrolo[2,3-d]pyrimidin-4-one (186 g, 1.23 mol) in pyridine (2 L) was treated with trimethylacetyl chloride (475 g, 3.94 mol, 485 mL, 3.2 eq) at 90° C. for 2 h, to give a mixture of N(2)-monoacylated and N(2), N(7)-bisacylated material. The solvent was evaporated and the residue was taken up in aqueous ammonia (37% NH3, 310 mL) and MeOH (2 L), and stirred at rt for 30 min, to selectively cleave the N(7)-pivaloyl group. The solid was collected by filtration, washed with water (500 mL×5), and dried on high vacuum to give the title compound as a solid (193 g). Concentration of the mother liquor provided additional solid material, which was collected, washed with water (50 mL×5), and dried (77 g). The combined yield was 93% (HPLC purity 98.6%). tR: 4.57 min. 1H-NMR (DMSO-d6) δ 12.00, (br. s, 1H), 7.40 (br. s, 1H), 6.96 (q, 1H), 6.40 (q, 1H), 1.24 (s, 9H).

Provenance & Evidence