Abstract: Formation of micro-fluidic systems is normally achieved using a multi-wafer fabrication procedure. The present invention teaches how a complete micro-fluidic system can be implemented on a single chip. The invention uses only dry etch processes to form micro-chambers. In particular, it makes use of deep reactive ion etching whereby multiple trenches of differing depths may be formed simultaneously. Buried micro-chambers are formed by isotropically increasing trench widths using an etchant that does not attack the mask so the trenches grow wider beneath the surface until they merge. Deposition of a dielectric layer over the trenches allows some trenches to be sealed and some to be left open. Micro-pumps are formed by including in the micro-chamber roof a layer that is used to change chamber volume either through electrostatically induced motion or through thermal mismatch as a result of its being heated.

Abstract: Design of a micro-mirror switching device and its fabrication in single crystal silicon are described. The device is composed of three main elements: silicon mirror plate with metal-mirror, secondary actuator, and hinge/spring mechanism to integrate the mirror plate with the actuator. p-n junction is first formed on p-type silicon. Trenches are then etched in n-silicon to define the device element boundaries and filled with silicon dioxide. Three layers of sacrificial oxide and two structural poly-silicon layers are deposited and patterned to form device elements. Novel release processes, consisting of backside electrochemical etching in potassium-hydroxide, reactive ion etching to expose oxide-filled trenches from the bottom, and hydrofluoric acid etching of sacrificial oxide layers and oxide in silicon trenches, form the silicon blocks; those that are not attached to structural poly-silicon are sacrificed and those that are attached are left in place to hold together the switching device elements.

Abstract: Formation of micro-fluidic systems is normally achieved using a multi-wafer fabrication procedure. The present invention teaches how a complete micro-fluidic system can be implemented on a single chip. The invention uses only dry etch processes to form micro-chambers. In particular, it makes use of deep reactive ion etching whereby multiple trenches of differing depths may be formed simultaneously. Buried micro-chambers are formed by isotropically increasing trench widths using an etchant that does not attack the mask so the trenches grow wider beneath the surface until they merge. Deposition of a dielectric layer over the trenches allows some trenches to be sealed and some to be left open. Micro-pumps are formed by including in the micro-chamber roof a layer that is used to change chamber volume either through electrostatically induced motion or through thermal mismatch as a result of its being heated.

Abstract: A process to form a capillary that is well insulated from its environment is described. Said process has two stages. The first stage, which is the same for both of the invention's two embodiments, comprises forming a micro-channel in the surface of a sheet of glassy material. For the first embodiment, this sheet is bonded to a layer of oxide, that lies on the surface of a sheet of silicon, thereby sealing in the capillary. After all silicon has been selectively removed, a thin membrane of oxide remains. Using a low temperature bonding process, a second sheet of glassy material is then bonded to this membrane. In the second embodiment, the silicon is not fully removed. Instead, the oxide layer of the first embodiment is replaced by an oxide/nitride/oxide trilayer which provides improved electrical insulation between the capillary and the remaining silicon at a lower level of inter-layer stress.

Abstract: The present invention provides the crystalline bisulfate salt of the formula ##STR1## which is found to have unexpectedly high solubility/dissolution rate and oral bioavailability relative to the free base form of this azapeptide HIV protease inhibitor compound.

Abstract: A purine salt of the formula ##STR1## wherein Y.sub.1 is chloro, bromo, or iodo, and R.sub.1, R.sub.2, R.sub.3, and R.sub.4 are independently selected from alkyl and substituted alkyl is reacted with the compound of the formulaZ.sub.1 --Xto yield the purine of the formula ##STR2## wherein x is a leaving group, and Z.sub.1 is a protected form of the carbohydrate surrogate Z.

Abstract: The present invention relates to novel 7-oxabicycloheptane carboxylic acid prostaglandin analog intermediates which may be used to prepare a final anti-thrombotic, anti-vasospastic product, and to methods for preparing the same.

Abstract: A purine salt of the formula ##STR1## wherein Y.sub.1 is chloro, bromo, or iodo, and R.sub.1, R.sub.2, R.sub.3, and R.sub.4 are independently selected from alkyl and substituted alkyl.

Abstract: A method is provided for preparing carboxylic acid intermediates of the structure ##STR1##

Abstract: A method is provided for preparing homochiral maleimide intermediates of the structure ##STR1## wherein R.sup.7, R.sup.8 and R.sup.9 are as defined herein by reacting a homochiral amine of the structure ##STR2## with maleic anhydride and a silylating agent. The maleimide intermediate is used in the enantio-selective preparation of thromboxane A.sub.2 receptor antagonists.

Abstract: Racemic Feist's acid is treated with (R)-(+) -.alpha.-methylbenzylamine to yield (1R-trans)-3-methylene -cyclopropane-1,2-dicarboxylic acid, (R)-.alpha.-methylbenzyl-amine (1:1) salt. This salt can then be converted to (1R-trans)-3-methylene-1,2-cyclopropanedicarboxylic acid, dimethyl ester which is an intermediate in the preparation of the antiviral agent [1R-(1.alpha.,2.beta.,3.alpha.)]-2-amino-9-[2,3-bis(hydroxymethyl)cyclobut yl]-1,9-dihydro-6H-purin-6-one. The improved process also enables the recovery of racemic Feist's acid from the resolution.

Abstract: The protected cyclobutanone of the formula ##STR1## is treated with a dialkylaluminum chloride, an alkylaluminum dichloride, a trialkylaluminum compound, hydrogen in the presence of the catalysts ruthenium black or ruthenium on alumina, diphenyl-silane in the presence of tris(triphenylphosphine) rhodium (I) chloride, or iridium tetrachloride to yield the corresponding diprotected cyclobutanol. This compound is useful as an intermediate in the preparation of antiviral agents.

Abstract: A method is provided for preparing carboxylic acid intermediates of the structure ##STR1##

Abstract: A method is provided for preparing carboxylic acid intermediates of the structure ##STR1##

Abstract: The protected cyclobutanone of the formula ##STR1## is treated with a dialkylaluminum chloride, an alkylaluminum dichloride, a trialkylaluminum compound, diphenylsilane in the presence of tris(triphenylphosphine) rhodium (I) chloride, or iridium tetrachloride to yield the corresponding diprotected cyclobutanol. This compound is useful as an intermediate in the preparation of antiviral agents.

Abstract: A method is provided for preparing carboxylic acid intermediates of the structure ##STR1## wherein an aldehyde of the structure ##STR2## is prepared and subjected to a Horner-Emmons reaction to form the ester of the structure ##STR3## and the ester is hydrogenated to the carboxylic acid which may be used in making the final anti-thrombotic--anti-vasospastic compounds.

Abstract: A method is provided for preparing oxazole intermediates of the structure ##STR1## (wherein R is alkyl) wherein an oxazoline of the structure ##STR2## is oxidized employing an oxidizing agent such as cupric bromide, a base such as 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), and a non-hydride donor amine base such as hexamethylenetetraamine (HMTA). The resulting oxazole may be hydrolyzed to the final anti-thrombotic - anti-vasospastic compounds.

Abstract: A method is provided for preparing bromooxazole intermediates of the structure ##STR1## wherein a vinyl compound of the structure ##STR2## wherein X.sup.1 and X.sup.2 are independently H and Br, is treated with a metal halide such as cupric bromide, and a base such as 1,8-diazabicyclo-[5.4.0]undec-7-ene (DBU). The resulting bromooxazole may be hydrolyzed and hydrogenolyzed to the final anti-thrombotic-anti-vasospastic compounds.

Abstract: Racemic Feist's acid is treated with (R)-(+)-.alpha.-methylbenzylamine to yield (1R-trans)-3-methylenecyclopropane-1,2-dicarboxylic acid, (R)-.alpha.-methylbenzylamine (1:1) salt. This salt can then be converted to (1R-trans)-3-methylene-1,2-cyclopropanedicarboxylic acid, dimethyl ester which is an intermediate in the preparation of the antiviral agent [1R-(1.alpha.,2.beta.,3.alpha.)]-2-amino-9-[2,3-bis(hydroxymethyl)cyclobut yl]-1,9-dihydro-6H-purin-6-one. The improved process also enables the recovery of racemic Feist's acid from the resolution.

Abstract: Racemic Feist's acid is treated with (R)-(+)-.alpha.-methylbenzylamine to yield (1R-trans)-3-methylenecyclopropane-1,2-dicarboxylic acid, (R)-.alpha.-methylbenzylamine (1:1) salt. This salt can then be converted to (1R-trans)-3-methylene-1,2-cyclopropanedicarboxylic acid, dimethyl ester which is an intermediate in the preparation of the antiviral agent [1R-(1.alpha.,2.beta.,3.alpha.)]-2-amino-9-[2,3-bis(hydroxymethyl)cyclobut yl]-1,9-dihydro-6H-purin-6-one. The improved process also enables the recovery of racemic Feist's acid from the resolution.