Chloromethyl Methyl Ether → tert-butyl 4-[1-{[2-(methoxymethyl)-2H-tetrazol-5-yl]methyl}-2,4-dioxo-6-phenyl-1,4-dihydrothieno[3,2-d]pyrimidin-3(2H)-yl]piperidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a stirred suspension of sodium hydride (206 mg, 60% dispersion in mineral oil) in 7 ml absolute THF in a sealed tube is added a solution of a tautomeric mixture of tert-butyl 4-[2,4-dioxo-6-phenyl-1-(1H-tetrazol-5-ylmethyl)-1,4-dihydrothieno[3,2-d]pyrimidin-3(2H)-yl]piperidine-1-carboxylate and 4-[2,4-dioxo-6-phenyl-1-(2H-tetrazol-5-ylmethyl)-1,4-dihydro-2H-thieno[3,2-d]pyrimidin-3-yl-]-piperidine-1-carboxylic acid tert-butyl ester (1.74 g; compound 14b) in absolute THF (7 ml) and absolute DMF (7 ml) at 0° C. After stirring for 40 min at 40° C. chloromethyl methyl ether (452 mg) dissolved in absolute DMF (3.5 ml) is added. The reaction mixture is stirred for 3 h at 50° C. and for 16 h at RT. The reaction is quenched by addition of a saturated aqueous solution of sodium bicarbonate and extracted with diethyl ether (two times). The combined organic phases are dried over magnesium sulfate, filtered and the solvent is removed under reduced pressure. The resulting residue is purified by flash chromatography [silica gel, eluent: cyclohexane/diethyl ether, 1/1 (v/v)] to give the separated title compounds as solids.

Provenance & Evidence