Patent ID: 6579971
Filing Date: 2003-06-17
Classification: C07D

Abstract:
A process for preparing 3,4-dehydroprolines and 3,4-dehydropiperidines of the formula I in whichR is hydrogen, C1-C6-alkoxy, â€”NHC1-C6-alkyl, â€”N(C1-C6-alkyl)2, OH, NH2 R1 is hydrogen, C1-C6-alkyl, Me3Si, C1-C6-alkyl-S R2 is Boc, C1-C6-acyl, mesyl, benzenesulfonyl, tosyl, trifluoroacetyl, A1-A3-peptide n is 1, 2 R4 is H, C1-C6-alkyl comprising the steps of reacting a pyrroline or dehydropiperidine derivative of the formula II with a strong base and a compound of the formula III in whichY is Cl, C1-C6-alkoxy, â€”NHC1-C6-alkyl, â€”N(C1-C6-alkyl)2, N(C1-C6-alkyl)OC1-C6, where R is not OH, or with carbon dioxide for R=OH and hydrolyzing the reaction product of II and III or with a compound of the formula IVR3â€”Xâ€ƒâ€ƒ(IV) in whichX is Cl, Br, I, MesO, TosO, triflate R3 is hydrogen, C1-C6-alkyl, Me3Si, C1-C6-alkyl-S or NH4 or R3â€”X is (C1-C6-alkyl-S)2.