Reaction #44024

Reaction equation

Dimethylcarbamoyl chloride

(8-(4-Chlorophenylsulfonyl)-9-ethyl-1,4-dioxa-8-azaspiro[4.5]decan-7-yl)methanol

(8-(4-chlorophenylsulfonyl)-9-ethyl-1,4-dioxa-8-azaspiro[4.5]decan-7-yl)methanol

triethylamine

N2

→

112

Yield 136.6%

(8-(4-chlorophenylsulfonyl)-9-ethyl-1,4-dioxa-8-azaspiro[4.5]decan-7-yl)methyl dimethylcarbamate

Yield 136.6%

Solvents

CH2Cl2

Conditions

Workup

1. 1
   workup.STIRRINGthe reaction stirred for 18 hours
2. 2
   ConcentrationThe reaction mixture was concentrated under reduced pressure, and equal portions of EtOAc and water
3. 3
   workup.ADDITIONwere added
4. 4
   ExtractionThe aqueous layer was extracted with several more portions of EtOAc
5. 5
   WashThe combined organic layers were washed with a dilute NaOH solution, 10% citric acid, brine
6. 6
   Dryingdried over Na2SO4
7. 7
   Concentrationconcentrated

Procedure

(8-(4-Chlorophenylsulfonyl)-9-ethyl-1,4-dioxa-8-azaspiro[4.5]decan-7-yl)methanol (111; 1.19 g, 3.18 mmol) and triethylamine (2.21 ml, 15.9 mmol) were added to CH2Cl2 (15 mL) in a flame-dried flask and placed tinder N2. DMAP (77.8 mg, 0.637 mmol) was added and the mixture stirred for 5 minutes. Dimethylcarbamoyl chloride (0.88 mL, 1.54 mmol) was added dropwise and the reaction stirred for 18 hours. The reaction mixture was concentrated under reduced pressure, and equal portions of EtOAc and water were added. The aqueous layer was extracted with several more portions of EtOAc. The combined organic layers were washed with a dilute NaOH solution, 10% citric acid, brine, dried over Na2SO4 and concentrated to yield 940 mg of 112 as a yellow oil. The material was purified by column chromatography using EtOAc/hexanes gradients to yield 836 mg (59%) of a mixture of cis/trans isomers.

Source