A method was developed for the synthesis of high-specific-activity 21-diazo-21[6,7-3Hdeoxycorticosterone, an analog of corticosterone. This analog was used as a photoaffinity label of a high affinity steroid-binding protein, human corticosteroid-binding globulin. Based on direct binding studies and crosscompetition experiments, this diazo derivative exhibited the requisite affinity (within a factor of 1.5 times that of corticosterone) and site specificity to qualify as an affinity labeling ligand. Purification and definition of the properties of the corticosteroid receptors have been frustrated by their low abundance in cytoplasm and irreversible loss of binding activity during isolation (1-4). In principle, these problems could be circumvented by site-specific covalent labeling of the receptor (5, 6). In a previous study, 21-diazo derivatives of corticosteroids exhibited reasonable affinities for intracellular receptors and functional activity in a toad bladder assay (5). In addition, covalent labeling of plasma proteins was obtained with 9a-bromo-21-diazo-21-[1,2-3H]deoxycorticosterone. The utility of this compound was limited, however, by the low specific activity (25 Ci/mol). We now report on the preparation of high-specific-activity 21-diazo-21- [6,7-3H] (5) with the following solvent systems: system A, benzene-ethyl acetate (1:2 vol/vol); system B, benzene-ethanol (6:1 vol/vol); system C, chloroform-ethyl acetate (1:3 vol/vol). Melting points, microanalyses, and. UV spectroscopy were performed as described (5). Catalytic tritiation was performed with the assistance of Dr. Chin-Tzu Peng and Mr. Ray Aune at the Lawrence Radiation Laboratory (Berkeley, Calif.). The reaction sequence used to prepare 21-diazo-21-[6,7-3H]deoxycorticosterone (compound V) is shown in Fig. 1. Compound II was obtained by treatment of compound I (2.0 g) with chloranil (6.5 g) in t-butanol (120 ml). The filtered mixture was evaporated, taken up in ether, washed with dilute NaOH and water, and reevaporated. The residue was crystallized from aqueous methanol; mp 171-174°[lit. mp 155-177° (8)], Xmax 286 nm. Compound-III was prepared by reaction of compound II (0.9 g in 10 ml of dioxane + 1.5 ml of H20) with sodium hypobromite (prepared from 0.3 ml of Br2 and 0.5 g of NaOH in 8 ml of H20) at 00. The reaction mixture was diluted with dioxane (4 ml), stirred for 2.5 hr at 00, treated with NaHSO3 (50 mg) for 15 min, extracted with ether, and acidified with HCL. The precipitate was washed with H20 and crystallized from aqueous acetone (mp 270-275°, Xmax 286 nm) (Anal. calcd. for C20H2604: C, 72.70; H, 7.93. Found: C, 72.54; H, 7.83). Compound IV [mp 251-255°, Xmax 242 nm, (E 1.55 X 104)] was prepared from compound I as described (5). Compound V [mp 1750 (dec), Xmax 247 nm (E 2.3 X 104)], with a shoulder at 280 nm, was prepared from compound IV as described (5). Tritium-labeled compound IV (at C6-C7) was obtained by catalytic tritiation of compound III in benzene-tetrahydrofuran solvent using 10% palladium on charcoal and carrier-fre...
SUMMARYThe preparation of 21-diazoprogesterone-6, 7-3H2 is described. Progesterone was dehydrogenated with chloranil to give A-dehydroprogesterone. Degradation of the pregnane side-chain with sodium hypobromite gave the corresponding carboxylic acid. Catalytic reduction with carrier-free tritium followed by treatment with oxalyl chloride and then diazomethane afforded 21-diazoprogesterone-6, 7-3H2 with a specific activity of 42 Ci/mmol. (1) and 21-diazo-21-deoxycorticosterone-6,7-3H2 (7 Ci/mmol) (2).The utility of the 9a-bromo analog was limited, however, by its low specific activity. This report describes the procedure used to synthesize high-specific-activity 21-diazoprogesterone-6, 7-'H2.
The synthesis of N-cyano-2-aza-A-nor-5alpha-androstan-17beta-ol acetate is described. Cyclization of 1,4-dibromo-1,4-seco-2,3bisnor-5alpha-androstan-17beta-ol acetate with benzylamine in the presence of potassium iodide gives the N-benzyl-2-aza-A-nor steroid. Debenzylation with cyanogen bromide (Von Braun reaction) affords the N-cyano-2-aza-A-nor steroid, which has androgenic activity slightly weaker than that of the corresponding thia compound. The results indicate that NCN may be substituted for--S--as well as for =S. This compound is the first hormonally active steroid containing nitrogen as a heteroatom in the perhydrocyclopentanophenanthrene nucleus.
Das Dehydro‐methyltestosteron‐acetat (I) wird zum Keton (II) hydriert, das mit Chromtrioxid zur Dicar‐ bonsäure (IIIa) gespalten wird.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.