Ethyl bromoacetate → HCID 19848832, compound

Participants

Reaction Conditions

Reaction Steps

Under anhydrous conditions, under a nitrogen atmosphere 5.31 ml. of 1.6 molar n-butyllithium in hexane is charged to a flask containing 80 ml. dry tetrahydrofuran at -78° C. A solution of 1.2 ml. (848 mg., 8.4 mmole) freshly distilled diisopropylamine is added dropwise and the resulting mixture stirred at -78° C. for three hours. Then a solution of 3.1 g. (6.85 mmole) methyl 5-benzyloxy-2,2-dimethyl-7-(1,1-dimethylheptyl)-3,4-dihydro-2H-benzopyran-4-carboxylate (Example 88, Part B) in 10 ml. THF is added slowly and the resulting mixture stirred for three hours at -78° C. To this is added dropwise 1.40 g. (8.4 mmole) ethyl bromoacetate and the mixture stirred for 15 minutes. The reaction is quenched by addition of acetic acid and the mixture allowed to warm to ambient temperature. The product was isolated by the procedure described in Example 3, Part A, to obtain 2.89 g. (78%) of the desired diester, Rf 0.29, hexane/ethyl ether, 3:1.

Provenance & Evidence