Reaction #10281

Reaction equation

phosgene

5-chloro-1-pentanol

N,N-diethylaniline

4-aminobutyraldehyde diethylacetal

triethylamine

→

(4,4-diethoxybutyl)carbamic acid 5-chloro-pentyl ester

Solvents

toluene

toluene

ethyl acetate

Conditions

Workup

1. 1
   FiltrationThe mixture was filtered
2. 2
   Concentrationthe filtrate was concentrated
3. 3
   Filtrationfiltered
4. 4
   workup.ADDITIONthe solution was added dropwise to an ice-
5. 5
   workup.STIRRINGThe reaction mixture was stirred at room temperature for 15 hours
6. 6
   Filtrationfiltered
7. 7
   Concentrationconcentrated
8. 8
   OtherPurification by silica gel chromatography
9. 9
   Washeluting with 10% ethyl acetate in hexane

Procedure

To an ice-cooled solution of 1.93M phosgene in toluene (31 mL, 60 mmole) was added dropwise a solution of 5-chloro-1-pentanol (4.9 g, 40 mmole) and N,N-diethylaniline (5.97 g, 40 mmole) in toluene (40 mL). The reaction mixture was stirred at ambient temperature for 4 hours. The mixture was filtered, and the filtrate was concentrated. The residue was taken up in ethyl acetate, filtered, and the solution was added dropwise to an ice-cooled solution of 4-aminobutyraldehyde diethylacetal (7.09 g, 44 mmole) and triethylamine (4.45 g, 44 mmole) in ethyl acetate (60 mL). The reaction mixture was stirred at room temperature for 15 hours, filtered and concentrated. Purification by silica gel chromatography, eluting with 10% ethyl acetate in hexane, gave (4,4-diethoxybutyl)carbamic acid 5-chloro-pentyl ester (11.4 g,) as an oil.

Source