共查询到20条相似文献,搜索用时 31 毫秒
1.
2.
L. N. Ivanova A. N. Lobov A. A. Fatykhov R. M. Sultanova S. S. Zlotskii V. A. Dokichev 《Russian Journal of Organic Chemistry》2011,47(11):1755-1760
Reactions of 5-(allyloxymethyl)- and 5-(methallyloxymethyl)-5-ethyl-1,3-dioxanes with methyl diazoacetate catalyzed by Rh2(OAc)4 or Cu(OTf)2 in the presence of [bmim]+Cl−, [bmim]+BF4
−, and [bmim]+PF6
− proceed regioselectively at the C=C bond and lead to the formation of the corresponding cyclopropane-containing 1,3-dioxanes
in yields up to 62%. 相似文献
3.
4.
5.
6.
本文首先用5-(3-吡啶)-2H-四唑乙酰基酰肼与芳酰基异硫氰酸盐反应制备成化合物1-[5-(3-吡啶)-2H-四唑乙酰基]-4-芳酰氨基硫脲化合物1a~j, 然后用冰醋酸回流处理1a~j得到一系列化合物5-[5-(3-吡啶)-2H-四唑亚甲基]-2-芳酰氨基-1,3,4-噻二唑2a~j . 化合物1a~b在强碱介质中首先发生降解, 然后进行环化反应 . 相似文献
7.
5—Br—PADAP为显色剂吸光光度法测定微量碘酸根的研究 总被引:11,自引:3,他引:11
在硫酸介质中,2-(5-溴-2-吡啶偶氮)-5-二乙氨基酚(5-Br-PADAP)与IO_3~-及SCN~-生成红色缔合物,用于吸光光度法分析微量IO_3~-,加入表面活性剂吐温-80可以提高测定的灵敏度和选择性。在最大吸收波长550nm处,可测IO_3~-浓度范围为0~2.45μg·ml~(-1),摩尔吸光系数ε为8.2×10~4,离子缔合物的组成比为5-Br-PADAP:IO_3~-:SCN~-=2:1:4。经测定硝酸钠和氯酸钾中IO_3~-的回收率为97.3%~101.5%,结果令人满意。 相似文献
8.
9.
Tartakovskii V. A. Ermakov A. S. Vinogradov D. B. 《Russian Journal of Organic Chemistry》2002,38(9):1339-1342
Russian Journal of Organic Chemistry - 相似文献
10.
11.
The hydrogenation of 2′, 3′-O-isopropylidene-5-methyluridine (1) in water over 5% Rh/Al2O3 gave (5 R)- and (5 S)-5-methyl-5, 6-dihydrouridine (2) , separated as 5′-O-(p-tolylsulfonyl)- (3) and 5′-O-benzoyl- (5) derivatives by preparative TLC. on silica gel and ether/hexane developments. The diastereoisomeric differentiation at the C(5) chiral centre depends upon the reaction media and the nature of the protecting group attached to the ribosyl moiety. The synthesis of iodo derivatives (5 R)- and (5 S)- 4 is also described. The diastereoisomers 4 were converted into (5 R)- and (5 S)-2′, 3′,-O-isopropylidene-5-methyl-2, 5′-anhydro-5, 6-dihydrouridine (7) . 相似文献
12.
13.
N. Saemian G. Shirvani H. Matloubi 《Journal of Radioanalytical and Nuclear Chemistry》2006,268(3):545-548
Summary Two 1,2,3-triazole anticonvulsants, 1-(4-methylsulfone-phenyl)-5-(4-fluoro-phenyl)-5-[14C]-1,2,3-triazole and 1-(4-sulfonamide-phenyl)-5-(4-fluoro-phenyl)-5-[14C]-1,2,3-triazole, both labeled with carbon-14 in the 5-position were prepared from para-fluoro-benzonitrile-[cyano-14C]. 相似文献
14.
15.
The reactivity of 5-methyl-4-(pyrrolidin-1-yl)-5H-furan-2-one with aldehydes and with acyl chlorides followed by reduction was studied. The aldol condensation gave predominantly the anti aldol product when the acylation-reduction sequence led exclusively to the syn product. The use of a chiral pyrrolidine, (S)-2-methoxymethylpyrrolidine (SMP), allowed the synthesis of enantio-enriched compounds, the acylation-reduction leading to the (R,R) addition product. 相似文献
16.
17.
18.
19.
铱(Ⅲ)与2-(5-溴-2-吡啶偶氮)-5-二甲氨基苯胺的显色反应及其应用 总被引:1,自引:0,他引:1
研究了试剂2_(5_溴_2_吡啶偶氮 )_5_二甲氨基苯胺 (5_Br_PADMA)与铱 (Ⅲ )的显色反应 ;在 pH4.75~6.00的HAc -NaAc缓冲溶液中 ,铱 (Ⅲ )与5_Br_PADMA形成摩尔比为1∶2型稳定的红色络合物 ,在0.6mol/LH2SO4溶液中 ,其最大吸收波长为558nm ,表观摩尔吸光系数为5.1×104L/(mol·cm) ,铱 (Ⅲ )含量在0~0.8mg/L范围内符合比尔定律 ,采用加入适量EDTA的方法消除了Fe3 + 、Co2 + 、Ni2 + 等干扰离子 ,建立了在二元络合物体系中测定微量铱 (Ⅲ )的灵敏度高、选择性好、简便、稳定的分光光度法 相似文献
20.
《Tetrahedron》1961,16(1-4):30-44
1-(Cyclohexenyl- and 1-cycloheptenylnitromethane have been used as starting substances to yield 2-nitro-2-(1′-cyclohexenyl)- and 2-nitro-2-(1′-cycloheptenyl)-propanediol-1,3 (B) respectively. By reacting them with formaldehyde and benzylamine or formaldehydes and cyclohexylamine, derivatives of tetrahydro-1,3-oxazine (B) have been prepared. Acid hydrolysis of tetrahydro-1,3-oxazine derivatives results in the formation of 3-hydroxy-2-nitro-2-(1′-cyclohexenyl)- and 3-hydroxy-2-nitro-2-(1′-cycloheptenyl)-propylamine derivatives (E). Both aminoalcohols (E) react with formaldehyde to again yield tetrahydro-1,3-oxazine derivatives (C).
Infra-red spectra of C and E and their hydrochlorides D and F were examined and structure assignments made of the principal bands. 相似文献