Hydrochloric Acid → 3-(5,6,7,8-Tetrahydropyrido[4',3':4,5]thieno[2,3-d]pyrimidin-4-ylamino)phenol

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Reaction Conditions

Reaction Steps

tert-Butyl 4-chloro-5,8-dihydropyrido[4′,3′:4,5]thieno[2,3-d]pyrimidine-7(6H)-carboxylate from Example 11A (1.00 g, 3.07 mmol) was dissolved in 2-propanol (10 mL). 3-Aminophenol (352 mg, 3.22 mmol) and a 4 M solution of gaseous hydrogen chloride in dioxane (38 μL, 0.15 mmol) were added, and the mixture was heated to 80° C. for 20 h. Subsequently, further 4 M hydrogen chloride in dioxane (1.54 mL, 6.14 mmol) was added, and the mixture was heated for additional 3 h. The precipitate was collected by suction filtration to yield 1.21 g of the title compound as hydrochloride salt. An analytical amount was dissolved in 1 M aqueous sodium hydroxide solution which was then concentrated in vacuo. The precipitate was collected by suction filtration and dried to yield the product as free base.

Provenance & Evidence