Dicyclohexylcarbodiimide → 4-Tert-butoxycarbonylamino-1-methyl-1h-pyrrole-2-carboxylic acid benzotriazol-1yl ester

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Reaction Steps

The Boc-imidazole-acid 12 (2 g, 8.3 mmol) was in dissolved in 10 ml of DMF and 1-hydroxybenzotriazole was added (1.2 g, 9 mmol) followed by DCC (2.4 g, 9 mmol). After 6 hours the precipitate was removed by filtration and washed with 4 ml of DMF. The DMF solution was added dropwise to 250 ml of well stirred ice water and the resulting precipitate was collected by vacuum filtration. The filter cake was ground and dried in vacuo over P2O5 to give (2.7 g, 89%) of 13 as a pale yellow power contaminated with a small amount of DCU (2.7 g, 89%). 1H NMR (DMSO-d6) δ 9.62 (s, 1H), 7.96 (s, 1H), 7.68 (d, 1H), 7.52 (d, 1H), 7.38 (d, 1H), 7.23 (s, 1H), 3.85 (s, 3H), 1.33 (s, 9H).

Provenance & Evidence