Ethyl Acetate → HCID 69585839, compound

Participants

Reaction Steps

To a solution of 2-amino-5-aminomethyl-4,7-dihydro-5H-thieno[2,3-c]pyran-3-carboxylic acid tert-butyl ester (0.53 g, 1.86 mmol, prepared as described in Example 17) in tetrahydrofuran (10 ml) was added, maleic acid (0.24 g, 2.05 mmol) and diisopropylcarbodiimide (0.58 ml, 3.72 mmol). The reaction mixture was heated to reflux for 3 h. and then allowed to cool to room temperature over an 18 hours period. The solvent was stripped off in vacuo and the residue diluted into ethyl acetate (50 ml). The organic phase was washed with saturated sodium bicarbonate (2×50 ml), 1% hydrochloric acid (2×20 ml), brine (3×50 ml), dried (MgSO4), filtered, and the solvent evaporated in vacuo affording an oil which was subjected to flash chromatography using a mixture of ethyl acetate/hexanes (6:4) as eluent. Pure fractions (Rf=0.25) were collected and the solvent evaporated in vacuo to give 0.60 g (90%) of 2-amino-5-(2,5-dioxo-2,5-dihydro-pyrrol-1-ylmethyl)-4,7-dihydro-5H-thieno[2,3-c]pyran-3-carboxylic acid tert-butyl ester as an oil.

Provenance & Evidence