Journal of Organic Chemistry p. 2700 - 2705 (1992)
Update date:2022-08-04
Topics:
Fisher, Lawrence E.
Muchowski, Joseph M.
Clark, Robin D.
Reaction of N-propenylbenzamides 4 and 9, obtained by LDA-induced isomerization of the corresponding N-allylbenzamides, 1, 8, and 14, with 2 equiv of sec-butyllithium or tert-butyllithium at low temperature regiospecifically generates the highly reactive N,ortho-dilithiated species (e.g., 5 and 17).These dilithio species react avidly with a wide spectrum of electophilic reagents, including alky halides, giving adducts which on hydrolysis with warm 50percent aqueous acetic acid are converted into ortho-substituted primary benzamides in excellent yields.Ortho-lithiation of N-propenylbenzamides is thus formally equivalent to ortho-lithiation of primary benzamides themselves.The utility of this important, previously unknown, synthetic operation is enhanced by the well-known facility with which the primary amide moiety can be transformed into other useful functional groups, as exemplified by the synthesis of 2-methoxy-6-methylbenzoic acid (12) and 2-methoxy-6-methylbenzonitrile (13) from N-propenyl-2-methoxybenzamide (9).N-Propenyl-o-toluamide (7) undergoes regiospecific dilithiation on nitrogen and on the methyl group under conditions analogous to those used for the N-propenylbenzamides.These dilithio species react with DMF or "Weinreb type" amides to give condensation products which cyclize to N-propenylisoquinolin-1(2H)-ones under mildly acidic conditions.Removal of the N-propenyl moiety under more strongly acidic conditions provides N-unsubstituted isoquinolin-1(2H)-ones with high overall efficiency.This process is exemplified by the synthesis of isoquinolin-1(2H)-one (23) and its 3-n-butyl congener 26 from N-propenyl-2-methylbenzamide (7).
View MoreZibo Xiaoguang Chemical Material Co., Ltd
Contact:15954099116
Address:Boshan Development Zone
Contact:86-28-66070694 13350079802
Address:Nanyan Road,Tianfu Road sichuan ,china
Contact:+86-371-55981030
Address:Room 1571, Macalline Soho, No.1, Shangdu Road, Zhengzhou, Henan
Shenzhen Feiming Science and Technology Co,. Ltd
Contact:+86-755-85232577
Address:#B2309, Fenglin International Center ,Jixiang Road, Longcheng street, LongGang District, Shenzhen city, Guangdong province, China.
Daicel Chiral Technologies (China)CO.,LTD
Contact:021-5046-0086*8
Address:Part C, FL 5, the 16th Building, No. 69, XiYa Road, WaiGaoQiao Free Trade Zone, Shanghai, 200131, P.R.China
Doi:10.1055/s-0031-1291042
(2012)Doi:10.1021/ol3024133
(2012)Doi:10.1021/jacs.0c06405
(2020)Doi:10.1016/j.tetlet.2012.07.095
(2012)Doi:10.1093/glycob/cwr172
(2012)Doi:10.1021/co300094n
(2012)