Reference

Carbonyl compounds and analogs as stabilizers for solutions of dialkyl pyrocarbonates, optionally containing polyisocyanates

Carbonyl compounds and analogs as stabilizers for solutions of dialkyl pyrocarbonates, optionally containing polyisocyanates. Kopp, Richard; Reichmann, Wolfgang (Bayer A.-G. , Fed. Rep. 4083-64-1 and 70-55-3 are also occured in this study. Ger.). Ger. Offen. DE 3231397 A1 1 Mar 1984, 20 pp. (German). (Germany). CODEN: GWXXBX. CLASS: IC: C09K003-00; C08G018-70; C08J009-08; C08F004-40; D06L003-02; A01N047-06; A23L003-34; C03C011-00. APPLICATION: DE 82-3231397 24 Aug 1982. DOCUMENT TYPE: Patent CA Section: 37 (Plastics Manufacture and Processing) Acyl halides, S acid amides, esters, or isocyanates, (thio)ureas, etc. are stabilizers for the title compns., useful in the prepn. of polyurethane foams. Thus, when a mixt. of polymethylenepolyphenylene isocyanate [9016-87-9] 200, di-Me pyrocarbonate (I) [4525-33-1] 2, and urea [57-13-6] 1 g was heated at 60° for 21 days, the residual I content was 0.68%, compared with 0.18% in the absence of urea. .

p-Toluenesulfonyl isocyanate as a novel derivatization reagent to enhance the electrospray ionization and its application in the determination of two stereo isomers of 3-hydroxyl-7-methyl-norethynodrel in plasma

p-Toluenesulfonyl isocyanate as a novel derivatization reagent to enhance the electrospray ionization and its application in the determination of two stereo isomers of 3-hydroxyl-7-methyl-norethynodrel in plasma.Several substances are used for example 100239-45-0 and 4083-64-1 which are their cas registry numbers. Zuo, Ming; Gao, Ming-jie; Liu, Zhen; Cai, Lei; Duan, Geng-Li ( Department of Pharmaceutical Analysis, School of Pharmacy, Fudan University, Shanghai 200032, Peop. Rep. China). Journal of Chromatography, B: Analytical Technologies in the Biomedical and Life Sciences, 814(2), 331-337 (English) 2005 Elsevier B.V. CODEN: JCBAAI. ISSN: 1570-0232. DOCUMENT TYPE: Journal CA Section: 1 (Pharmacology) Section cross-reference(s): 2 In this paper, p-toluenesulfonyl isocyanate was reported as a novel derivatization reagent with strong nucleophilic reactivity for the hydroxyl compds. The derivatization for the 2 pharmacol. active 3-hydroxyl metabolites, 3a-hydroxyl-7-methyl-norethynodrel and 3b-hydroxyl-7-methyl-norethynodrel by p-toluenesulfonyl isocyanate can be accomplished in 2 min under room temp. The off-line derivatization procedure introduced an easily ionizable sulfonylcarbamic ester moiety to the metabolites. This greatly improved the analyte's sensitivity in neg. electrospray ionization and enabled us to achieve the desired lower limit of quantitation at 100 pg/mL in blood plasma. Therefore, a sensitive high performance liq. chromatog.-mass spectrometry (HPLC-MS) method for the anal. of the 2 stereo isomers was developed. The method had been validated to be accurate, precise, and sensitive, and can be used for the metab. pharmacokinetic study of tibolone in human subjects. .