Sodium Sulfite → HCID 19065141, compound

Participants

Reaction Steps

2-Ethyl-7-azabenzothiazole (2.95 g) was dissolved in dichloromethane (30 ml), and meta-chloroperbenzoic acid (4.7 g) was added to the solution at room temperature. After 3.5 hours, meta-chloroperbenzoic acid (2.3 g). was further added. After completion of a reaction, the reaction mixture was treated with an aqueous solution of sodium sulfite while chilling with ice water. The thus-treated reaction mixture was diluted with dichloromethane, and the resultant organic layer was washed with aqueous sodium hydrogencarbonate, water and saline in that order, and dried. The solvent was distilled out to obtain 2-ethyl-7-azabenzothiazole-7-oxide (2.69 g). This compound was added to dichloromethane (27 ml), and dimethylaminocarbamoyl chloride (4.16 g), trimethylsilyl cyanide (5.69 ml) and triethylamine (6.3 ml) were successively added to conduct a reaction for 8 hours at room temperature. Trimethylsilyl cyanide (2.5 ml) and dimethylaminocarbamoyl chloride (2.5 ml) were further added. After the reaction was conducted for 2 days at room temperature, aqueous sodium hydrogencarbonate was added to the reaction mixture, followed by stirring for 1 hour. The reaction mixture was subjected to extraction with ethyl acetate, and the resultant organic layer was washed with water, dried and evaporated. After purifying the residue through a silica gel column (eluthion with dichloromethane: methanol=200:1), recrystallization from dichloromethaneisopropyl ether was conducted to form 2-ethyl=6-cyano-7-azabenzothiazole (1.37 g). The intended compound was obtained in accordance with the same procedure as that of Example 106 except that the above compound was used in place of 2-ethyl-6-chlorobenzothiazole. Physical properties of this compound are described below.

Provenance & Evidence