Formaldehyde → 4-Chloro-6,7,8,9-tetrahydro-5H-dipyrido[2,3-b;4',3'-d]pyrrole-6-carboxylic acid methyl ester

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Reaction Conditions

Reaction Steps

A suspension of 2-amino-3-(4-chloro-1H-pyrrolo[2,3-b]pyridin-3-yl)-propionic acid methyl ester (3.5 g, 10 mmol) in pyridine (25 mL) was treated with formaldehyde solution (37% in water, 0.90 mL) and the resulting mixture was heated to 100° C. for 1.25 hours. The mixture was allowed to cool to ambient temperature then evaporated in-vacuo. The resultant residue was treated with saturated aqueous sodium carbonate solution (15 mL) and the resultant solid collected by filtration and washed with water (20 mL). The filtrate was extracted with 20% methanol in dichloromethane (6×25 mL). The combined organic phase was combined with solid and concentrated in-vacuo to afford the title compound as a brown residue (2.1 g, 87%). LCMS (Method B): RT=2.36 min, M+H+=266. 1H NMR (400 MHz, DMSO-d6): 11.66 (s, 1H), 8.02 (d, J=5.2 Hz, 1H), 7.06 (d, J=5.1 Hz, 1H), 4.01-3.71 (m, 3H), 3.69 (s, 3H), 3.19 (dd, J=15.4, 4.7 Hz, 1H), 2.94 (dd, J=15.4, 8.9 Hz, 1H).

Provenance & Evidence