Fungicidal spirocyclic amines

Pfrengle, US Patent 5,849,802 (December 15, 1998) Assignee American Cyanamid Company Utility Phytopathogenic Fungicide 

Lithium diisopropylamine (0.2 mol) dissolved in 300 ml THF at —20°C was added to ethyl 4-t-butylcyclohexylcarboxylate (0.2 mol), stirred 1 hour, and the temperature lowered to —70°C. Thereafter, allylbromide (0.2 mol) was added and the mixture allowed to come to ambient temperature overnight. The mixture was quenched with NH4CI solution, the organic layer concentrated, and the product distilled at 75-82 °C at 0.03 mbar and 46 g of product isolated as a colorless oil. 

To a solution of m-CPBA (0.08 mol) in CHjClj was added the product from Step 1 (0.067 mol) in 200 ml CH2CI2 and the reaction stirred overnight. Thereafter the mixture was filtered and 17 g product isolated as a colorless oil. 

Lithium aluminum hydride (0.132 mol) in 100 ml THF was added to the product from Step 2 (0.063 mol) dissolved in THF and the mixture stirred overnight. Excess lithium aluminum hydride was hydrolyzed using aqueous Na2C03 solution and the hydrolysis product filtered from solution. The product was isolated and re-crystallized in light petroleum, mp = 93 °C. 

Oxalylchloride (0.165 mol) dissolved in 50 ml CH2CI2 was added to 21 ml DMSO in 50 ml CH2CI2, the reaction cooled to -70°C, the product from Step 3 (0.075 mol) added, and the mixture stirred 30 minutes. To this was added 100 ml TEA and the reaction warmed to ambient temperature. Thereafter the reaction mixture was washed with brine, dried,15g impure product isolated with a mp = 68-72 °C and used without further purification Step 5. 

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