4,5-dihydro-4,4-dimethyl-2-(2-thienyl)-oxazole → HCID 70060418, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 9.0 g at 4,5-dihydro-4,4-dimethyl-2-(2-thienyl)oxazole in 200 ml of tetrahydrofuran, cooled to -78° C., is added 20 ml of a 2.5 molar solution of n-butyl lithium in hexane. The mixture is stirred -78° C. for 15 minutes and at 0° C. for 30 minutes. To the stirred solution is added 6.0 g of 2-methylbenzoxazepine-4-one. The mixture is stirred at room temperature for 16 hours quenched with ice cold water and extracted with chloroform. The extract is concentrated to dryness and 100 ml of 40% H2SO4 is added. The mixture is refluxed for 4 hours, cooled to room temperature and filtered to give 9,10-dihydro-4,10-dioxo-4H-thieno [2,3-c][1]benzazepine. The solid is washed with water to give 2.5 g of crystals. The solid is dissolved in 100 ml of dry tetrahydrofuran and 1.0 g of lithium aluminum hydride added. The mixture is refluxed for 16 hours, chilled and ice cold water is added dropwise. The mixture after dilution with water is extracted with chloroform-methanol (3:1) and the extract dried (MgSO4). The solvent is removed and the residue chromatographed over silica gel with ethyl acetate-hexane (1:1) as solvent to give 1.8 g of solid; Mass spectrum (CI) 202 (M+H).

Provenance & Evidence