139314-01-5Relevant articles and documents
An efficient O-dealkylation procedure for the synthesis of (3aS,cis)- 1,2,3,3a,8,8a-hexahydro-1,3a,8-trimethylpyrrolo[2,3-b]indol-5-yl-3,4-dihydro- 2(1H)-isoquinolinecarboxylate
Gao, Zhongli,Lee, Thomas B. K.,Rauckman, Barbara S.
, p. 331 - 333 (2000)
The title compound is synthesized in high yields and purity from (-)- eserethole (2a) via a lithium bromide catalyzed hydrobromic acid O- dealkylation procedure as the key step.
Method of preparation of physostigmine carbamate derivatives from eseretholes
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, (2008/06/13)
This application relates to a new process for the preparation of a product of the formula STR1 wherein R is loweralkyl; R1 is hydrogen, loweralkyl, lowercycloalkyl, lowercycloalkylloweralkyl, lowerbicycloalkyl, aryl or arylloweralkyl; R2 is loweralkyl, lowercycloalkyl, lowercycloalkylloweralkyl, lowerbicycloalkyl, aryl or arylloweralkyl; or R1 and R2 taken together with the nitrogen atom to which they are attached from a 3,4-dihydro-2H(1H)-isoquinoline group; X is loweralkyl, loweralkoxy, halogen or trifluoromethyl; and m is 0, 1 or 2; which process comprises (a) contacting a compound of formula II STR2 wherein R, X and m are as defined above and R3 is loweralkyl, with aluminum chloride followed by tartaric acid to afford a compound of formula III STR3 wherein R, X and m are as defined above; (b) contacting the reaction mixture containing the compound of Formula III either (1) with an isocyanate of the formula R1 NCO and obtaining a product of the formula I wherein R2 is hydrogen; or (2) with a compound of formula IV STR4 wherein R4 is hydrogen or loweralkyl in the presence of a carboxylic acid of the formula wherein R5 is loweralkyl to afford a compound of formula V STR5 wherein R, R4, X and m are as above; contacting the reaction mixture containing the compound of Formula V with a compound of the formula wherein R1 and R2 are as above; and isolating the product of Formula I.