摘要:
1-Methylcarbapenem derivatives of the formula: ##STR1## wherein R.sup.1 is hydrogen atom or a hydroxy-protecting group, R.sup.2 is hydrogen atom or an ester residue, R.sup.3 is hydrogen atom or a lower alkyl group, or salts thereof, which have excellent antimicrobial activities and are useful as an antimicrobial drug.
摘要:
A method for removing substituted or unsubstituted allyl group from .beta.-lactam compound having substituted or unsubstituted allyl group-protecting carboxyl group, which comprises treating said .beta.-lactam compound with palladium catalyst in the presence of allyl-scavenger in aqueous organic solvent, by which the substituted or unsubstituted group can be easily and effectively removed under moderate conditions so that the desired compound can be obtained in high yield at low cost.
摘要:
Disclosed is a process for preparing a .beta.-lactam compound represented by the formula: ##STR1## wherein R.sup.1 represents a hydroxy-substituted lower alkyl group or an amino group each of which may be protected; R.sup.2 represents hydrogen atom or an ester residue; X represents a methylene group which may be substituted by a lower alkyl group, sulfur atom or a group represented by the formula: --A--CH.sub.2 -- where A represents sulfur atom, oxygen atom or methylene group; and W represents an active ester residue of hydroxyl group, or a salt thereof, which comprises the steps of treating a 1-aza-3-thia-bicycloalkane compound represented by the formula: ##STR2## wherein R.sup.1, R.sup.2 and X have the same meanings as defined above, or a salt thereof with a base in the presence of a desulfurizing agent and then reacting the resulting compound with an active esterifying agent of hydroxyl group.
摘要:
Process for preparing carbapenem derivative of the formula [I], which comprises subjecting azetidinone compound of the formula [II] to intramolecular cyclization reaction together with elimination reaction of the group of --SR.sup.4, followed by re-adding said group of --SR.sup.4 to the 2-position of the carbapenem skeleton of the intramolecularly cyclized compound, which is industrially useful as process for preparing carbapenem antimicrobials or synthetic intermediate therefor. ##STR1## wherein R.sup.1 is protected or unprotected hydroxy-substituted lower alkyl group, R.sup.2 is hydrogen atom or ester residue, R.sup.3 is hydrogen atom or lower alkyl group, and the group of --SR.sup.4 is group which can be used as substituent at 2-position of the carbapenem antimicrobials.
摘要:
A method for removing tri-substituted silyl group from .beta.-lactam compound having a tri-substituted silyl group-protecting hydroxy group, which comprises treating with an acid and a fluoride selected from alkali metal fluoride, alkaline earth metal fluoride and hydrogenfluoride of organic or inorganic amine, by which the tri-substituted silyl group can be easily and effectively removed under moderate conditions so that the desired compound can be obtained in high yield at low cost.
摘要:
Disclosed is a process for preparing a .beta.-lactam compound represented by the formula: ##STR1## wherein R.sup.1 represents a hydroxy-substituted lower alkyl group or an amino group each of which may be protected; R.sup.2 represents hydrogen atom or an ester residue; X represents a methylene group which may be substituted by a lower alkyl group, sulfur atom or a group represented by the formula: --A--CH.sub.2 -- where A represents sulfur atom, oxygen atom or methylene group; and W represents an active ester residue of hydroxyl group,or a salt thereof, which comprises the steps of treating a 1-aza-3-thia-bicycloalkane compound represented by the formula: ##STR2## wherein R.sup.1, R.sup.2 and X have the same meanings as defined above, or a salt thereof with a base in the presence of a desulfurizing agent and then reacting the resulting compound with an active esterifying agent of hydroxyl group.
摘要:
An aluminum alloy casting material for heat conducting is provided, wherein the thermal conductivity is improved of an aluminum alloy casting material whereof the castability is improved by the addition of silicon where said invention is characterized by being an aluminum alloy casting material with excellent thermal conductivity, comprising 5-10.0% by mass of silicon, 0.1-0.5% by mass of magnesium and the remainder comprising aluminum and inevitable impurities, and whereon aging treatment has been performed.
摘要:
The present invention provides an aluminum alloy for die castings that has superior castability and corrosion resistance. The amounts of Mn, Fe and Cu contained in the aluminum alloy components for die castings were determined to have a considerable effect on the corrosion resistance of the aluminum alloy. Therefore, the aluminum alloy for die castings of the present invention contains 9.0 to 12.0% by weight of Si, 0.20 to 0.80% by weight of Mg, and 0.7 to 1.1% by weight of Mn+Fe, the Mn/Fe ratio is 1.5 or more, the amount of Cu as impurity is controlled to 0.5% by weight or less, and the remainder is composed of aluminum and unavoidable impurities.
摘要:
A high strength aluminum alloy casting obtained by casting an aluminum alloy comprised of 7.5 to 11.5 wt % of Si, 3.8 to 4.8 wt % of Cu, 0.45 to 0.65 wt % of Mg, 0.4 to 0.7 wt % of Fe, 0.35 to 0.45 wt % of Mn, and the balance of Al and not more than 0.2 wt % of unavoidable impurities, wherein this aluminum alloy has 0.1 to 0.3 wt % of Ag added to it or contains 0.1 to 1.0 wt % of at least one element selected from the group of second additive elements comprised of Rb, K, Ba, Sr, Zr, Nb, Ta, V, and Pd and rare earth elements, and a method of production of a high strength aluminum alloy casting comprising the steps of filling a melt of an aluminum alloy in a mold to obtain a casting, taking out the aluminum alloy casting from the mold, solubilizing the high strength aluminum alloy casting by heating in a temperature range of 495 to 505° C. for 2 to 6 hours, quenching the high strength aluminum alloy casting after the solubilization, and age hardening the high strength aluminum alloy casting by heating in a temperature range of 160 to 220° C. for 2 to 6 hours after quenching.