Isopropyl azodicarboxylates

In further studies relevant to the mechanism of the Mitsunobu reaction, the reaction of diphenylphosphine (40) with di-isopropyl azodicarboxylate (41) was found to give a mixture of products one of which was assigned structure (44) formed via (42) and (43). The reaction of trico-ordinate phosphorus compounds with ortho-quinones,p-ketoalkenes and p-ketoimines is also a well-established source of pentaco-ordinate phosphorus compounds but in some cases the dipolar ion structure is more stable. Thus the reaction of (4Sab) with (46) produced the dipolar ion structures (47ab) but on the other hand, reaction of (45b) with the quinone imine (48) produced what appeared to be an equilibrium mixture of (49) and the pentaco-ordinate structure (50). The 1,3,2-X o -diazaphospholenes (Slab) have proved to be useful synthetic reagents in that on hydrolysis they yield the bis-hydroxylamine (52) which reacts with benzaldehyde to form the imidazoline (53). ... 

Thioesters.—Mixed anhydrides prepared from 2,4,6-trichlorobenzyl chloride and a carboxylic acid react with various thiols in the presence of 4-dimethyl-aminopyridine to give thioesters in 78—86% isolated yield.Somewhat less impressive yields were obtained in a few of the cases studied when l-fluoro-2,4,6-trinitrobenzene was used to couple the acid and the thiol.Treatment of 1-acylimidazoles with thiols in the presence of a catalytic amount of Mg(OEt)2 furnishes thioesters in good yields. Diphenyl-2-oxo-3-oxazolinylphosphonate brings about effective reaction between acids and thiols. Thiolacetates are efficiently prepared using the reaction of an alcohol with triphenylphosphine and di-isopropyl azodicarboxylate in the presence of thiolacetic acid/ A synthesis of some amino-acid derivatives containing the thioester functional group is achieved by the reaction of a vinyloxyborane with a Schiffs base (Scheme 56). ... 

Ac, acetyl AIBN, azobis(isobutanonitrile) All, allyl AR, aryl Bn, benzyl f-BOC, ferf-butoxycarbonyl Bu, Butyl Bz, benzoyl CAN, ceric ammonium nitrate Cbz, benzyloxycarbonyl m-CPBA, m-chloroperoxybenzoic acid DAST, diethylaminosulfur trifluoride DBU, l,8-diazabicyclo[5.4.0]undec-7-ene DCC, /V. /V - d i eye I oh e x y I c ar bo -diimide DCM, dichloromethyl DCMME, dichloromethyl methyl ether DDQ, 2,3-dichloro-5,6-dicyano-l,4-benzoquinone DEAD, diethyl azodicarboxylate l-(+)-DET, L-(+)-diethyl tartrate l-DIPT, L-diisopropyl tartrate d-DIPT, D-diisopropyl tartrate DMAP, 4-dimethylaminopyridine DME, 1,2-dimethoxyethane DMF, /V./V-dimethylformamide DMP, 2,2-dimethoxypropane Et, ethyl Im, imidazole KHMDS, potassium hexamethyldisilazane Me, methyl Me2SO, dimethyl sulfoxide MOM, methoxymethyl MOMC1, methoxymethyl chloride Ms, methylsulfonyl MS, molecular sieves NBS, N-bromosuccinimide NIS, /V-iodosuccinimide NMO, /V-methylmorpho-line N-oxide PCC, pyridinium chlorochromate Ph, phenyl PMB, / -methoxvbenzyl PPTs, pyridiniump-toluenesulfonate i-Pr, isopropyl Py, pyridine rt, room temperature TBAF, tetrabutylammonium fluoride TBS, ferf-butyl dimethylsilyl TBDMSC1, f-butylchlorodimethylsilane Tf, trifhioromethylsulfonyl Tf20, trifluoromethylsulfonic anhydride TFA, trifluoroacetic acid THF, tetrahydrofuran TMS, trimethylsilyl TPAP, tetra-n-propylammonium perruthenate / -TsOH. / -toluenesulfonic acid... 

Procarbazine Hydrochloride, USP. Procarbazine hydrochloride, Malulane. MIH. NSC-77213, N-isopropyl-o-(2-methylhydrazine)-p-toluamide. is prepared from N-iso-propyl-/>-toluamide in a process involving condensation with diethyl azodicarboxylate. methylation with methyl itxlide and base, and acid hydrolysis. Although soluble in water, it is unstable in solution. Capsules containing the equivalent of SO mg of procarbazine as its hydrochloride ore supplied. 

Tetrafluoroethylene and diethyl azodicarboxylate yield diethyl 3,3,4,4-tetrafluoro-l,2-diazetidine-l,2-dicarboxylate on heating. This reaction has been further investigated using other esters, and also with other fluoro-olefins, CF CFH, CF iCF-CFs, and CF CFC1. Di-isopropyl ester (79) is hydrolysed by concentrated sulphuric acid at room temperature to 3,3,4,4-tetrafluoro-l, 2-diazetidine (80). 

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