摘要:

AbstractPregnenolone‐17α −3H was synthesized by reaction of 17α‐bromo‐pregnenolone with tritiated acetic acid (CH3CO23H) and zinc metal dust. The distribution of the label in the product was studied; about 98% was at the 17‐position and the remainder was randomly distributed on the steroids nucleus. It was also found that when pregnenolone was stirred with deuterated acetic acid (CH3CO22H) and zinc metal dust for a longer period of time (22 hr) and in relatively high concentration, the protons of the C21‐methyl group (˜57%) were exchanged

ISSN:0022-2135    

DOI:10.1002/jlcr.2590070202

出版商:John Wiley&Sons, Ltd.    

年代:1971

数据来源: WILEY

摘要:

AbstractTwo vinyl phosphates, 3‐hydroxy‐N,N‐dimethyl‐cis‐crotonamide dimethyl phosphate, and itsN‐monomethyl analog, 3‐hydroxy‐N‐methyl‐cis‐crotonamide dimethyl phosphate, labeled with32P and14C in three positions, have been synthesized in milligram amounts. The radiosynthesis routes are reported and the effect of reduced scale preparation is discussed. As the compounds exist in geometric isomers, methods for their separation have been developed. The purity of the cis‐isomers was determined to be 98 to 99%. The yield of 3‐hydroxy‐N,N‐dimethyl‐cis‐crotonamide dimethyl phosphate labeled with32P was 38%, with14C‐O‐methyl 73% and with14C‐N‐methyl 34%. The yield of 3‐hydroxy‐N‐methyl‐cis‐crotonamide dimethyl phosphate labeled with32P was

ISSN:0022-2135    

DOI:10.1002/jlcr.2590070203

出版商:John Wiley&Sons, Ltd.    

年代:1971

数据来源: WILEY

摘要:

AbstractIn order to fully understand the metabolic transformations of adrenocortical steroids, labelled 3α, 11β 17α,211‐tetrahydroxy‐5α‐pregnan‐20‐one, Reichstein's Compound C was required. Starting from hydrocortisone, the synthesis of [1−3H]‐Reichstein's Compound C has

ISSN:0022-2135    

DOI:10.1002/jlcr.2590070204

出版商:John Wiley&Sons, Ltd.    

年代:1971

数据来源: WILEY

摘要:

AbstractA method for preparing tritium‐labelled ryanodine is described. The alkaloid was first brominated, and the bromoryanodines were separated from the reaction mixture by thin layer chromatography; NMR analysis at this stage showed substitution of pyrrole protons by bromine. Bromoryanodine was first hydrogenated, and the product was purified and characterized as ryanodine, to establish the feasibility of the method. Tritium was then reacted with bromoryanodine to yield labelled ryanodine with a specific activity of 2.85 Ci/mmole. No detectable isotope exchange occurred when the labelled alkaloid was incubated in aqueous media at pH 7.0 and 30°

ISSN:0022-2135    

DOI:10.1002/jlcr.2590070205

出版商:John Wiley&Sons, Ltd.    

年代:1971

数据来源: WILEY

摘要:

AbstractThe synthesis of 11,11‐dideuterooleic acid is described. The Wittig reaction is used to introduce the carbon‐carbon double bond, giving a mixture of which better than 90% is the desired cis‐isomer. Two alternative routes gave deuterium incorporation of 95 and>

ISSN:0022-2135    

DOI:10.1002/jlcr.2590070206

出版商:John Wiley&Sons, Ltd.    

年代:1971

数据来源: WILEY

摘要:

Abstract6‐n‐Propyl‐2‐thiouracil‐6−14C was prepared from sodium butyrate‐1−14C, with a radiochemical yield of 34%. Butyryl chloride‐1−14C was prepared from butyric acid‐1−14C and condensed with sodio ethylacetoacetate to yield ethyl β‐oxohexanoate‐β−14C. The β‐keto ester was condensed with thiourea in sodium ethoxide to

ISSN:0022-2135    

DOI:10.1002/jlcr.2590070207

出版商:John Wiley&Sons, Ltd.    

年代:1971

数据来源: WILEY

摘要:

AbstractPentachlorophenol−14C6was synthesized by chlorinating phenol−14C6using aluminum chloride as a catalyst. Purification of the labeled pentachlorophenol involved the precipitation of the labeled product from an aqueous alkali solution with hydrochloric acid and two sublimations. Proof of radiochemical purity was determined using thick layer chromatography and autoradiography. Internal liquid scintillation counting techniques were used to determine the specific activity of the compo

ISSN:0022-2135    

DOI:10.1002/jlcr.2590070208

出版商:John Wiley&Sons, Ltd.    

年代:1971

数据来源: WILEY

摘要:

AbstractStarting with trichloromethane‐(14C), tetrachloroethylene‐(14C) and tetrachloromethane‐(14C) are prepared by cracking of octachloropropane‐(14C) (6a). The mechanism of catalytic and thermal cracking of6aare di

ISSN:0022-2135    

DOI:10.1002/jlcr.2590070209

出版商:John Wiley&Sons, Ltd.    

年代:1971

数据来源: WILEY

摘要:

AbstractUracil was tritiated to uracil‐5‐t by electrolytic reduction of 5‐bromouracil in tritiated water. No secondary chemical or radio‐chemical reactions too

ISSN:0022-2135    

DOI:10.1002/jlcr.2590070210

出版商:John Wiley&Sons, Ltd.    

年代:1971

数据来源: WILEY

摘要:

Abstract14C‐uniformly ring labeled 3,3′,5,5′‐tetra‐tert‐butyldiphenoquinone was synthesized from 2,6‐di‐tert‐butylphenol. Chemical purity was established by mixed melting point, thin‐layer and gas‐liquid chromatography. Radiochemical purity was determined using auto‐radiography in conjunction with thin‐layer chromatography and liquid scintillation techniques. Structure was confirmed by elemental analysis, ultraviolet‐visible and infrared spectroscopy and

ISSN:0022-2135    

DOI:10.1002/jlcr.2590070211

出版商:John Wiley&Sons, Ltd.    

年代:1971

数据来源: WILEY