Propionic 3-iodo

Standnikow has prepared several of the esters of menthol by heating magnesium iodo-mentholate with the esters of ethyl alcohol. For example, with ethyl acetate, propionate, and benzoate the corresponding menthyl esters were obtained. These bodies have the following boiling-points —... 

Propionic acid, 2-iodo-3-nitro-, ethyl ester [Propanoic acid, 2-iodo-3-mtro-, ethyl ester], 65 2//-Pyran, 3,4-dihydro-, 51 2//-PYR AN-2-ONE, 49 2H Pyran 2-one, 5 bromo 5,6-dihydro, 50 27/-PYRAN-2-ONE, 5,6 DIHYDRO-, 49 PYRIDINE, 2,3,4,5 TETRAHYDRO, 118 Pyridines, -substituted, 34 a Pyrone-6-carboxyhc acid [2H Pyran-6-Larboxyhc acid 2-oxo ], 51 Pyrroles, 34... 

Purification of 2-(4 -[ I]iodo-biphenyl-4-sulfonylamino)-3-(l//-indol-3-yl)-propionic acid and 2-(4 -[ I]iodo-biphenyl-4-sulfonylamino)-3-(lff-indol-3-yl)-propionamide... 

The derivative 90 was obtained by condensation of the purpurin-18-A-hexylimide-17-propionic acid with aminolactose heptaacetate in the presence of benzotriazol-l-yloxy-tris(dimethylamino)phosphonium hexafluorophosphate (BOP) followed by the deacetylation procedure. The lactose-photosensitiser conjugate linked by an ethylene moiety was also prepared by following a similar approach. The purpurin-18-methyl ester 81 was converted into /V-(3-iodobenzyl)/ /evo-purpurin-18-7V-hexylimide-17-propionic ester by hydrogenation over Pd/C followed by reaction with 3-iodo-benzylamine. Afterwards, the propargyllactose heptaacetate reacted with A-(3-iodobenzyl)rMeio-purpurin-18-A-hexylimide-l 7-propionic ester in the presence of tris(dibenzylidieneacetone)dipalladium(0) (Pd2-dba3) which, after deacetylation conditions, afforded the derivative 89 (Fig. 9).68... 

Propiolic acid, 58,43 Propionaldehyde, 58, 80, 82 Propionic acid, 2-iodo-3-mtro-, ethyl ester, 56, 65... 

D Fouques, J Landry. Study of the conversion of asparagine and glutamine of proteins into diamino-propionic and diaminobutyric acids using [bis(trifluoroacetoxy)iodo]benzene prior to amino acid determination. Analyst 116 529-531, 1991. 

The di-sodium derivative is condensed with /3-iodo-propionic ester to form y-cyanopentane-ay -tricav-boxylic ester ... 

Copper or silver can be used to condense /3-iodo-propionic acid to adipic acid, and also for condensing a-brom-propionic ester to dimethyl succinic ester... 

RX. n-butyl bromide n-dodecanyl iodide cyclohexyl iodide ethyl bromo acetate methyl 2,3-di-O-acetyl-4-O-benzoyl-6-bromo-6-deoxy-ot-D-glucopyranoside methyl 2,3,4-tri-0-acetyl-6-deoxy-6-iodo-0 -D glucopyranoside l,2 3,4-di-0-isopropylidene-6-deoxy-6-iodo-a-D-galactopyranose methyl 2(R)-[(tert-butoxycarbonyl)amino]-3-iodo-propionate cyclic bis(trifluoromethyl)oxazolidinone bromide. 

The above directions are based upon the methods of Hoogewerff and Van Doip, as modified by Holm and by Hale and Honan. -Alanine has also been prepared by the action of h3q)obromite upon succinimide and hydrolysis of the resulting /3-ureidopropionic acid by the action of ammonia upon /3-iodo-propionic acid by the hydrolysis of methyl carbomethoxy-/8-aminopropionate, obtained by the action of sodiiun methoxide on succinbromimide by the reduction of 3-nitrosopropionic acid by heating ethyl acrylate with alcoholic ammonia from succinyl-glycine ester by the azide synthesis and by the action of liquid ammonia upon methyl acrylate. ... 

The first member of the ethylene series of acidsj viz., propen-oic acid, or as it is commonly known, acrylic acid, is a sharp smelling liquid which boils at 140° and melts at 7 . It readily forms addition products. With hydrogen it yields propionic acid with hydrogen iodide, j3-iodo propionic acid and with water, jS-hydroxy propionic acid. This last acid, which we will consider later (p. 245), because of this relation to acrylic acid, is also known as hydraoylic acid. From these compounds just mentioned acrylic acid may be formed by the loss of the same elements. 

From Propionic Acid.—The simplest method of synthesis is the one which shows the relation of hydracrj lic acid to propionic acid and proves that it is the Z>g/a-hydroxy acid. When /8-iodo propionic acid is boiled with water, or with aqueous silver hydroxide, hydracrylic acid is obtained. 

The isomeric alpha-hydroxy acid is prepared from a-iodo propionic acid in exactly the same way as the e/o-acid is prepared from the beta-... 

Some insight into the mechanisms of the iodine-promoted carbonylation has been obtained by radioactive tracer techniques [17] and low-temperature NMR spectroscopy [18]. The mechanism involves the formation of HI, which in a series of reactions forms with rhodium a hydrido iodo complex which reacts with ethylene to give an ethyl complex. Carbonylation and reductive elimination yield propionic acid iodide. The acid itself is then obtained after hydrolysis. The rate of carboxylation was reported to be accelerated by the addition of minor amounts of iron, cobalt, or manganese iodide [19]. The rhodium catalyst can be stabilized by triphenyl phosphite [20]. However, it is doubtful whether the ligand itself would meet the requirements of an industrial-scale process. 

A still further advance in this field is the successful substitution of iodine and of nitro-groups by electrolysis. On electrolyzing propionic acid and potas-ium iodide in aqueous solution -iodo-propionic acid was formed, due to the intermedia essf i i tlQn of succinic acid ... 

The active ester AT-succinimidyl 3-(2-p3 ridyldithio)propionate (SPDP) is the classical reagent to modify proteins with pyridyldithiopropyl (PDP) groups (20). If the protein to be modified contains many free Cys-residues this creates the risk of carrier-carrier conjugation. In this case it is possible to block the free thiols with iodo- or bromoacetic acid (or amide) before reaction with SPDP (or to use a different conjugation method, as described in Section 3.2). 

---