7-bromo-2,3,4,5-tetrahydro-1-benzoxepin-5-ol

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 254 ml (0.6 mole) of a 1.7 molar solution of tert.-butyllithium in n-pentane is slowly added dropwise under argon to a stirred solution of 48.6 g (0.2 mole) of 7-bromo-5-hydroxy-2,3,4,5-tetrahydro-1-benzoxepin in 550 ml of absolute THF at -90° C. to -100° C. The mixture is subsequently stirred at -78° C. for 1 hour and then, at this temperature, a solution of 24 ml (0.24 mole) of N-formylmorpholine in 180 ml of absolute THF is added dropwise while stirring vigorously. The mixture is stirred at -78° C. for 1 hour and subsequently allowed to warm to 0° C., and is diluted with diethyl ether and hydrolyzed with ice-water. After extraction several times with diethyl ether, the combined organic extracts are washed with water and saturated brine and dried over sodium sulfate, and the solvent is stripped off in vacuo. 40.7 g of yellowish oil are obtained and reacted further without purification. while stirring vigorously The mixture is stirred at -78° C. for 1 hour to warm to 0° C. After extraction several times with diethyl ether the combined organic extracts are washed with water and saturated brine dried over sodium sulfate

Conditions: temp:10.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 104.9 g (0.64 mole) of 2,3-dihydro-1-benzoxepin-5(4H)-one are dissolved at room temperature in 780 ml of glacial acetic acid and then, while stirring vigorously at 10° C., 113.9 g (0.64 mole) of N-bromosuccinimide are introduced in portions so that the temperature does not exceed 18°-20° C. (about 30 min). The reaction is complete after about 4 hours (TLC check) and the mixture is poured into 3 l of vigorously stirred ice-water and then stirred for 30 minutes. The solid produced which is initially oily crystallizes completely after some time. The solid is filtered off with suction and washed with about 5 l of water. It is dried over calcium chloride in vacuo and crystallized in cyclohexane. does not exceed 18°-20° C. (about 30 min) stirred for 30 minutes The solid produced which is initially oily crystallizes completely after some time The solid is filtered off with suction washed with about 5 l of water It is dried over calcium chloride in vacuo crystallized in cyclohexane