Molecules, Volume 5, Issue 12

Members of genus Swertia (Gentianaceae) have been the source of many active xanthones.[...]

Katritzky's well-established chemistry of benzotriazole [1] was applied to the synthesis of 1,2,3,4- tetrahydro-b-carboline, which have been traditionally prepared by Pictet-Spengler condensation2, Fischer cyclisation and other methods3.[...]

5-(Indol-3-yl)barbituric acid 3 was prepared by knovenagel condensation of indol-3-carboxaldehyde 1 and barbituric acid 2 in ethanol using piperidine as a base [1,2].[...]

The title compound was obtained by dehydration of the corresponding diacid 1 (12.1 g, 55 mmol) by boiling in acetyl chloride (50 ml) for four hours.[...]

The experimental procedure follows the general synthesis of arylalkynes reported by Sonogashira [1].[...]

All the following operations were performed under an inert atmosphere using standard vacuum line techniques. Trimethyloxosulfonium iodide (2, 0.73 g, 3.3 mmol) [1] was suspended in anhydrous DMSO (6 mL) and sodium hydride (80 % suspension in mineral...

To the epoxide 1 (1 g, 2.32 mmol) in acetone (50 ml) [1] was added dropwise at 0°C a solution of CrO3 (0.7 g, 7 mmol) in acetone (20 ml).[...]

To a mixture of (0.85 g, 4.9 mmol) of metachloroperoxybenzoic acid (mCPBA) [1,2] and (1.63 g, 19.6 mmol) of sodium hydrogenocarbonate (NaHCO3) in 20 ml of dichloromethane was added (1 g, 2.42 mmol) of 1 in 10 ml of CH2Cl2.[...]

To sodium hydride (0.34 g, 13.96 mmole) carefully washed with anhydrous benzene under nitrogen (to eliminate mineral oil from the commercial product) [1], was added 0.8 ml (9.27 mmol) of dimethylcarbonate (freshly distilled) in dry benzene (20 ml).[...]

8-Dihydro-3-methyl-7-amino-[1,2,4]triazino[3,4-b][1,3,4]thiadiazine 2 was prepared by the cyclocondensation of 4-amino-6-methyl-3-thio-1,2,4-triazin-5-one 1 with chloro-acetonitrile in the presence of triethylamine in refluxing CH3CN.[...]