129660-12-4Relevant articles and documents
A new route for manufacture of 3-cyano-1-naphthalenecarboxylic acid
Ashworth,Bowden,Dembofsky,Levin,Moss,Robinson,Szczur,Virica
, p. 74 - 81 (2003)
3-Cyano-1-naphthalenecarboxylic acid is an intermediate required for manufacture of tachykinin receptor antagonists. The 1,3-disubstitution pattern on the naphthalene skeleton complicates the synthesis of this cyano acid. Previous literature-based chemistry is unattractive for large-scale manufacture due to stoichiometric use of mercury salts, low yield, and other operational difficulties. An attractive new route has been developed by establishing the 1,3-substitution on the carbon atoms destined for only one-half of the naphthalene 2-ring system, via 3-bromocoumalate, and then building up the rest of the naphthalene ring system by Diels-Alder addition of 3-bromocoumalate to in situ-generated benzyne. The resulting 4-bromo-2-naphthoate was converted to the required cyanoacid by transformation of ester to nitrile followed by carbonylation of the bromo substituent. The new route has been scaled up successfully and offers significant advantages over previous literature chemistry in terms of improved process environmental implications, improved yield, lower cost, and improved robustness and ease of operation at larger scales of operation.
The synthesis of some 2H-pyran-2-one derivatives
Kvita,Sauter
, p. 883 - 889 (2007/10/02)
Derivatives of 6-unsubstituted 2H-pyran-2-one have been synthesized by several different methods. The 4-chloro-2H-pyran-2-one (9) is the most important, since it serves as starting material for the synthesis of different 4-substituted 2H-pyran-2-ones (Sch
