p-Toluenesulfonic acid → 4-Chloro-6-methyl-10,10-dioxo-2-[(pyridin-3-ylmethyl)-amino]-10,11-dihydro-5-oxa-10lambda*6*-thia-dibenzo[a,d]cycloheptene-8-carboxylic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

Pyridine-3-carboxyaldehyde (0.1 mL, 1.08 mmol) and p-toluene sulfonic acid (in catalytic amount) were added to a suspension of Example 35j (0.4 g, 1.08 mmol) in benzene (40 mL). The reaction mixture was refluxed using Dean-Stark apparatus for 4 h. It was concentrated, treated with methanol, refluxed for 4 h, and stirred at 25° C. overnight. Sodium cyanoborohydride (0.076 g, 1.2 mmol) was added and the reaction mixture was stirred for 3 h. It was treated with aqueous sodium bicarbonate solution and extracted with ethyl acetate. The organic layer was washed with water, brine, dried, concentrated and purified using flash chromatography (silica gel, methanol/chloroform) to obtain the title compound. Yield: 0.127 g, (25%); 1H NMR (DMSO-d6): δ 2.62 (s, 3H, CH3), 3.9 (s, 3H, CH3), 4.33 (d, 2H, CH2), 5.18 (s, 2H, CH2), 6.69 (d, 1H, Ar), 6.8 (d, 1H, Ar), 6.9 (t, 1H, NH), 7.38 (q, 1H, Ar), 7.75 (d, 1H, Ar), 8.1 (s, 1H, Ar), 8.17 (s, 1H, Ar), 8.48 (d, 1H, Ar), 8.6 (s, 1H, Ar).

Provenance & Evidence