addition of (R)-N-tert-butanesulfinyl imidates 8 to α,β-unsaturated pyrazolidinone 3a has been developed to afford pyrazolidinones 10 possessing three contiguous stereocenters with good to excellent yield and excellent diastereoselectivity. A two-step conversion of reduction and cyclization provides the bicyclic pyrazolopiperidine 12 in a good yield. A series of pyrazolopiperidine derivatives 18 with a
Synthesis of 4-nitro-1,2-hydrocarbyl pyrazolidines and process for
申请人:A. H. Robins Company, Inc.
公开号:US04309552A1
公开(公告)日:1982-01-05
4-Nitro-1,2-hydrocarbyl pyrazolidines are prepared by a novel route from 1,2-disubstituted hydrazines and 1,3-di-(secondary amino)-2-nitropropanes and reduced to the corresponding 4-amino-1,2-hydrocarbyl pyrazolidines, which latter compounds are intermediates in the preparation of certain pharmaceutical benzamides. The novel 4-nitro-1,2-hydrocarbyl pyrazolidines have the formula: ##STR1## wherein R.sup.1 and R.sup.2 are selected from loweralkyl, lowercycloalkyl or phenyl-loweralkyl and may be the same or different.
Synthesis of 4-amino-1,2-hydrocarbyl pyrazolidines via 4-nitro analogs
申请人:A. H. Robins Company, Inc.
公开号:US04358599A1
公开(公告)日:1982-11-09
4-Nitro-1,2-hydrocarbyl pyrazolidines are prepared by a novel route from 1,2-disubstituted hydrazines and 1,3-di-(secondary amino)-2-nitropropanes and reduced to the corresponding 4-amino-1,2-hydrocarbyl pyrazolidines, which latter compounds are intermediates in the preparation of certain pharmaceutical benzamides. The novel 4-nitro-1,2-hydrocarbyl pyrazolidines have the formula: ##STR1## wherein R.sup.1 and R.sup.2 are selected from loweralkyl, lowercycloalkyl or phenyl-loweralkyl and may be the same or different.