1 -acetylpyrrolidine

The pyrrolidine amides (1-acetylpyrrolidine and 1-propionylpyrrolidine) are prepared from the appropriate acid chloride and pyrrolidine (Mansson and Westfelt 1980). 

Stock solutions of 1-acetylpyrrolidine, and an internal standard (1-propionylpyrrolidine or 1-methylnaphthalene) in dioxane at a concentration of 10 mg ml-1 are prepared. A mixture of 1ml each of the 1-acetylpyrrolidine and internal standard solutions is used to establish the GC response factor. The calibration is made by injecting a 2-/A aliquot of the mixture into the gas chromatograph and measuring the peak areas. 

The acetylated lignin, dissolved in 1.0 ml of dioxane containing 5 mg of an internal standard, is treated with 1.0ml of a dioxane-pyrrolidine (1 1, v/v) solution which initiates the aminolysis reaction. The rate of the 1-acetylpyrrolidine formation is followed by periodically injecting 1-2/d of the reaction mixture into the gas chromatograph. The initial rapid phase is generally complete within 20 min, but a total of 60min is required to complete the deacetylation process. 

Fig. 7.2.1A,B. Rate of formation of 1-acetylpyrrolidine on A aminolysis of acetylated wood meal Norway spruce and of methanol on B periodate oxidation of wood meal. (Lai et al. 1990)...

The rate of 1-acetylpyrrolidine formation is followed as in the case of acetylated lignin, but the overall process is much slower and a 6-7-h reaction period may be required as illustrated in Fig. 7.2.1A for Norway spruce wood meal. 

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