Sodium Hydroxide → 7-Chlorothieno[3,2-b]pyridine

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Reaction Steps

Thieno[3,2-b]pyridin-7-ol (20 g, 0.132 mol) was suspended in phosphorous oxy chloride (80.9 g, 0.528 mol) and stirred at 100 C for 2 hours. The solution was cooled to room temperature and was poured over ice. The aqueous solution was neutralized with sodium hydroxide and the resulting precipitate was collected by filtration and washed with water. The filter cake was taken up in dichloromethane and dried over magnesium sulfate. The solution was filtered and the filtrate was concentrated to dryness to give 7-chlorothieno[3,2-b]pyridine as a brown liquid which solidified to a beige solid under high vacuum. Yield: 20.4 g (91%); MS [M+H]+ 169.9; 1HNMR (CDCl3) δ: 8.7 (d, 1H), 7.8 (d, 1H), 7.6 (d, 1H), 7.3 (d, 1H) ppm.

Provenance & Evidence