1-Pyrrolidineethanamine → 1-[[2-(Pyrrolidino)ethyl]amino]-7-methoxy-9H-xanthene-9-one

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Reaction Steps

A mixture of 1-chloro and 3-chloro isomers of 7-methoxyxanthone (32.6 g, 0.125 mole) of N-(2-aminoethyl)pyrrolidine (19.43 g, 0.17 mole) were refluxed in 150 mL of pyridine for 24 h with exclusion of moisture. The pyridine and excess of diamine was removed by vacuum distillation (ca. 12 mmHg, bath temp. 60°-72° C.), The distillation residue was dissolved in 200 mL of acetic acid, poured in 1.7 L water filtered and basified with NaOH pellets. The yellow-orange precipitate was filtered, washed with water an dried to give 34 g solid, which was chromatographed on silica gel. The first fraction was eluted with CHCl3. It was a mixture of starting chloroisomers and some minor by-products (18.5 g=56.7% melting range 135°-145° C. The desired compound was eluted with CHCl3 /EtOH (80:20) (13 g=30.7%), mp-93°-94° C. The analytical sample was recrystallized from ethanol, mp= 92°-93° C.

Provenance & Evidence