摘要:
7-(S)-Acylamino-3-hydroxymethyl-3-cephem sulfones are disclosed. These compounds are intermediates in the synthesis of 1-oxa .beta.-lactam antibiotics.
摘要:
A continuous flow-through mercury cathode electrolysis cell is described having a parallel anode and cathode and a non-conductive porous diaphragm separator. The cathode chamber is constructed so as to develop turbulence in the catholyte flowing therethrough to effect the maximum contact between the mercury and the catholyte solute and to promote removal therefrom of any gaseous by-products. Built-in heat exchangers provide efficient control of temperature sensitive electrolyses.
摘要:
Descarboxylysergic acid prepared from 2,3-dihydro-8.beta.-hydroxy-6-methyl-9-ergolene or from penniclavine has oxytocic, serotonin antagonist, prolactin inhibition and muscle contracting activities.
摘要:
A torsional vibration damper (1) has an input assembly (2,6,7) and a reactor plate (25) with coil springs (40) circumferentially spaced about a center axis of the damper to absorb vibration between the input assembly and reactor plate. Each coil spring (40) includes a plurality of active coils (50) and partial end coils (44). The active coils have a pitch greater than the diameter (d) of the wire (11) and the partial end coils have a pitch equal to the diameter of the wire. A flattened arcuate surface (42) is formed on the partial end coil which spans less than a full coil turn. A distal tip (46) of the end coil has a thickness that is a fraction of the diameter of the wire that is inversely proportional to the amount of arcuate flattened surface of the end coil section. The gap (66) between the tip and the adjacent coil is also inversely proportional to the amount of arcuate spanning surface of the end coil section.
摘要:
This invention encompasses 7-(S)-acylamino-3-acetoxymethyl-3-cephem-4-carboxylic acid sulfones and the epimerization process for making them. The epimerization process employs an organic nitrogen base reagent having a pKa between about 9.0 to about 11.5. The compounds of this invention are intermediates in the synthesis of 1-oxa-.beta.-lactam antibiotics.
摘要:
An azetidin-2-one-4-sulfinic acid represented by the formula ##STR1## is reacted with Pb(OAc).sub.4 in liquid SO.sub.2 containing CuII ion to provide isomeric cyclization products of the formulas ##STR2## wherein R is e.g. benzyl, phenoxymethyl, benzyloxy, diphenylmethoxy, and R.sub.1 is a carboxy-protecting group. The products of the process are useful intermediates for 1-oxa-.beta.-lactam antibacterials.
摘要:
N-substituted-2-(R)-(sulfinic acid)-3-(S)-(acylamino)-4-oxo-azetidines, which are useful as intermediates in 1-oxa .beta.-lactam antibiotics, are synthesized by electrolytic reduction of 7-(S)-acylamino-3-hydroxymethyl-3-cephem-4-carboxylic acid compounds.
摘要:
Descarboxylysergic acid prepared from 2,3-dihydro-8.beta.-hydroxy-6-methyl-9-ergolene or from penniclavine has oxytocic, serotonin antagonist, prolactin inhibition and muscle contracting activities.
摘要:
A process for preparing 3-4-cis-.beta.,.beta.-(4)-substituted and 3-4-trans,.beta.,.alpha.-(4)-substituted azetidinones is provided. Also provided are novel 4,4-disubstituted azetidinones.