Trifluoroacetic acid → (E)-N-Methyl-N-(3-methylbenzofuran-2-ylmethyl)-3-(2,3,4,5-tetrahydro-1H-pyrido[2,3-e][1,4]diazepin-7-yl)acrylamide

Participants

Reaction Steps

A solution of (E)-7-{2-[methyl-(3-methylbenzofuran-2-ylmethyl)carbamoyl]vinyl}-1,2,3,5-tetrahydro-pyrido[2,3-e][1,4]diazepine-4-carboxylic acid tert-butyl ester (0.38 g, 0.80 mmol) in CH2Cl2 (4 mL) was cooled in an ice bath and then treated with TFA (4 mL). After stirring for 2 h, the mixture was concentrated under vacuum. The residue was treated with saturated NaHCO3 (25 mL) and extracted with CH2Cl2/MeOH (4×═mL of a 98:2 mixture). The combined organic layers were dried over Na2SO4, filtered and concentrated to a light yellow solid. Purification by flash column chromatography (silica gel, CH2Cl2/MeOH, 92:8) gave the title compound (0.21 g, 70%) as a white powder and as a mixture of amide rotamers: 1H NMR (300 MHz, DMSO-d6) δ8.14 (br s, 1H), 7.68-7.63 (m, 1H), 7.50-7.40 (m, 3H), 7.26-7.20 (m, 2H), 7.04-6.72 (m, 1H), 5.10 (s, 1H), 4.83-4.72 (m, 2H), 3.89 (s, 2H), 3.30-3.26 (m, 2H), 3.22-3.04 (m, 5H), 2.31 (s, 3H), 1.70 (br s, 1H); MS (ESI) m/e 377 (M+H)+.

Provenance & Evidence