Hydrazine hydrate (1:1) → 2-amino-7-aminomethyl-4,7-dihydro-5H-thieno[2,3-c]pyran-3-carboxylic acid tert-butyl ester

Participants

Reaction Steps

To a mixture of 2-amino-7-(1,3-dioxo-1,3-dihydro-isoindol-2-ylmethyl)-4,7-dihydro-5H-thieno[2,3-c]pyran-3-carboxylic acid tert-butyl ester (6.0 g, 0.014 mol) in ethanol (100 ml) was added hydrazine hydrate (1.4 ml, 0.028 mol). The reaction mixture was heated at reflux for 1 h, cooled and the precipitate filtered off. The filtrate was evaporated in vacuo and to theresidue was added water (100 ml) and the resulting mixture was extracted with diethyl ether (2×100 ml). The combined organic extracts were washed with brine (100 ml), dried (Na2SO4), filtered and the solvent evaporated in vacuo affording 2.9 g (71%) of 2-amino-7-aminomethyl-4,7-dihydro-5H-thieno[2,3-c]pyran-3-carboxylic acid tert-butyl ester as an oil.

Provenance & Evidence