Detail of "22901-09-3"

Reference

Tandem SN2-Michael reactions for the preparation of simple five- and six-membered-ring nitrogen and sulfur heterocycles

Tandem SN2-Michael reactions for the preparation of simple five- and six-membered-ring nitrogen and sulfur heterocycles. Bunce, Richard A.; Peeples, Christopher J.; Jones, Paul B. (Dep. Chem., Oklahoma State Univ., Stillwater, OK 74078-0447, USA). J. Org. Chem., 57(6), 1727-33 (English) 1992. CODEN: JOCEAH. ISSN: 0022-3263. DOCUMENT TYPE: Journal CA Section: 27 (Heterocyclic Compounds (One Hetero Atom)) A one-pot tandem SN2-Michael addn. sequence has been developed for the prepn.Several substances with their cas registry numbers 22901-09-3 and 114746-82-6 may be metioned in this study. of five- and six-membered ring N and S heterocycles from 6- or 7-halo-2-alkenoate esters. Nitrogen-contg. rings can be prepd. by reaction of the w-halo-2-alkenoate ester with a primary amine in the presence of Et3N. The S analogs are generated by thiourea displacement of the halide followed by base hydrolysis of the isothiouronium salt. Yields are routinely in the 60-80% range. Thus, title reaction of (E)-2-BrCH2C6H4CH:CHCO2Et (I) with PhCH2NH2 in the presence of Et3N in EtOH gave 69% isoindoleacetate II (X = NCH2Ph, R = Et), whereas reaction of I with thiourea in EtOH followed by cyclization of isothiouronium salt in KOH-H2O gave 69% benzothiopheneacetic acid II (X = S, R = H). Expts. are described which elucidate the chronol. of the reaction sequences. Ring size and steric hindrance to the initial substitution reaction appear to be the only limitations of the procedure. .