[Cl-].[CH:2]1([CH2:7][CH2:8]C(Cl)=O)[CH2:6][CH2:5][CH2:4][CH2:3]1.[N-:12]=[N+]=[N-].[Na+].C[C:17](C)=[O:18]>O>[CH:2]1([CH2:7][CH2:8][N:12]=[C:17]=[O:18])[CH2:3][CH2:4][CH2:5][CH2:6]1The procedure is an adaptation of procedure in Org. Syn. Col. Vol II, p 846, Col. VI, p 95. A solution of 0.65 g of 3-cyclopentylpropionyl chloride (Example 253) in 10 ml of acetone is added dropwise to a 0° C. solution of 0.46 g of sodium azide in 5 ml of water When the addition is complete, stirring is continued for 1 hour. The mixture is extracted wink toluene, dried over anhydrous sodium sulfate and filtered. The toluene solution is added dropwise to 25 ml of toluene which is heated at reflux temperature. When the addition is complete, the reaction is refluxed until nitrogen evolution has ceased (ca 1 hour). The reaction is cooled and the resulting toluene solution of the corresponding isocyanate is then used a% in Example 124, 119, 99, and all new examples.
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