Reaction #1882

Reaction equation

dimethyl sulfoxide

oxalyl chloride

trans-7-chloro-5-(2-chlorophenyl)-1-isopropyl-2-oxo-1,2,3,5-tetrahydro-4,1-benzoxazepine-3-ethanol

triethylamine

→

trans-7-chloro-5-(2-chlorophenyl)-1-isopropyl-2-oxo-1,2,3,5-tetrahydro-4,1-benzoxazepine-3-acetaldehyde

Yield 92.5%

Solvents

methylene chloride

methylene chloride

methylene chloride

Conditions

Workup

1. 1
   workup.ADDITIONTo the mixture was added dropwise
2. 2
   workup.WAITtaking 15 minutes
3. 3
   workup.WAITtaking 5 minutes
4. 4
   Otherthe cooling bath was removed
5. 5
   workup.STIRRINGThe mixture was stirred for 10 minutes at room temperature, to which
6. 6
   workup.ADDITIONwas then added 1N hydrochloric acid (50 ml)
7. 7
   workup.STIRRINGby stirring
8. 8
   DryingThe methylene chloride layer was dried over anhydrous magnesium sulfate
9. 9
   workup.DISTILLATIONthe solvent was distilled off under reduced pressure

Procedure

A solution of oxalyl chloride (0.72 ml) in methylene chloride (10 ml) was cooled to -65° C., to which was added dropwise a solution of dimethyl sulfoxide (0.63 ml) in methylene chloride (2 ml) taking 5 minutes, followed by stirring for 5 minutes. To the mixture was added dropwise, taking 15 minutes, a solution of trans-7-chloro-5-(2-chlorophenyl)-1-isopropyl-2-oxo-1,2,3,5-tetrahydro-4,1-benzoxazepine-3-ethanol (2.5 g) obtained in Example 47 in methylene chloride (15 ml), which was stirred for 10 minutes. To the resultant mixture was added triethylamine (3.45 ml) taking 5 minutes, then the cooling bath was removed. The mixture was stirred for 10 minutes at room temperature, to which was then added 1N hydrochloric acid (50 ml), followed by stirring. The methylene chloride layer was dried over anhydrous magnesium sulfate, then the solvent was distilled off under reduced pressure to leave trans-7-chloro-5-(2-chlorophenyl)-1-isopropyl-2-oxo-1,2,3,5-tetrahydro-4,1-benzoxazepine-3-acetaldehyde (2.3 g) as an oily product.

Source