Bisulfite adduct

In addition to its industrial importance as an intermediate in the synthesis of vitamin K, menadione, or more specifically, salts of its bisulfite adduct, are important commodities in the feed industry and are used as stabilized forms in this appHcation. Commercially significant forms are menadione dimethyl pyrimidinol (MPB) (10) and menadione sodium bisulfite (MSB) (11). MSB is sold primarily as its sodium bisulfite complex. The influence of feed processing, ie, pelleting, on the stabiUty of these forms has been investigated (68). The biological availabiUties and stabiUty of these commercial sources has been deterrnined (69,70). 

The principal additive shrink-resist treatment uses the polymer Synthappret BAP (Bayer AG) which is a polypropylene oxide polyurethane containing reactive carbamoyl sulfonates (or isocyanate bisulfite adduct groups, —NHCOSO —Na" ). An aqueous solution of this polymer is padded onto woven fabrics, which are immediately dried. Other polymers may be appHed at the same time to modify the handle. 

Electrolysis, CH3CN, H2O, LiC104, 1.5 V, rt, 60-95% yield. The released quinone is removed by forming the bisulfite adduct, which can be washed out with water. 

Some internal oxidation-reduction reactions have been reported with the bisulfite adducts of naphtho[l,2-c]furoxan " and some... 

With Glyoxal-Sodium Bisulfite Adduct as Synthon... 

The Strecker reaction has been performed on the aldehyde 182 prepared from L-cysteine [86] (Scheme 28). The imine was formed in situ by treatment with benzylamine, then TMS cyanide was added to afford prevalently in almost quantitative yield the syn-diamine 183, which is the precursor of (-l-)-biotin 184. The syn selectivity was largely affected by the solvent, toluene being the solvent of choice. Since the aldehyde 182 is chemically and configurationally unstable, a preferred protocol for the synthesis of 183 involved the prehminary formation of the water-soluble bisulfite adduct 185 and the subsequent treatment with sodium cyanide. Although in this case the syn selectivity was lower, both diastereomers could be transformed to (-l-)-biotin. 

Further studies by Bode and co-workers have shown that enolate formation from a-chloroaldehydes and subsequent reaction with 4-oxo-enoates or unsaturated a-ketoesters 232 generates dihydropyranones 233 in excellent diastereo- and enantio-selectivities, and with impressively low catalyst loadings [90], This work has been extended to the generation of enolate equivalents from bisulfite adducts of a-haloaldehydes 234 under aqueous conditions (Scheme 12.50) [91]. 

Bisulfite Adduct. A bisulfite addition complex of an aldehyde or dialdehyde has been proposed for use as an antimicrobial agent [1858,1859]. The complex is less toxic than free glutaraldehyde. In oil wells, its digestion by the sulfate-reducing bacteria releases the free dialdehyde that controls the bacteria. In these ways, a more economic and environmentally safer use of antimicrobial additives is likely. 

The steroids aldosterone, cortisone, cortisol, 11-P-hydroxyandrostenedione, corticosterone, and rostenedione, 11-desoxycorticosterone, 17-hydroxy-progesterone, and progesterone have been performed on Ultrasphere ODS using methanokwater.19 Ranitidine N-[2-[[[5-[(dimethylamino)methyl]-2-furanyl]-methyl]thio]ethyl]-N1-methyl-2-nitro-l,l-ethenediamine has been separated using a p-Bondapak C18 column operated with acetoni-trile methanol water buffered with triethylamine phosphate.117 Pyridoxal-5 -phosphate and other B6 vitamers, including pyridoxamine phosphate, pyri-doxal, pyridoxine, and 4-pyridoxic acid, were separated as bisulfite adducts... 

Commercial 40% aqueous glyoxal or the glyoxal-sodium bisulfite adduct may be used satisfactorily with o-phenylenediamines to afford 2,3-unsubstituted quinoxalines the use of an irregular synthon or substrate is also illustrated in the following examples. 

Initially, 50 was converted into the benzoxazinone 51 by reaction with phosgene in the presence of triethylamine and 51 was isolated in 95% yield upon crystallization from methanol. Deprotection of the pMB group from 51 was accomplished with ceric ammonium nitrate (CAN) in aqueous acetonitrile. Efavirenz was isolated in 76% yield after crystallization from EtOAc-heptane (5 95), as shown in Scheme 1.19. There were two issues identified in this route. First, lequiv of ani-saldehyde was generated in this reaction, which could not be cleanly rejected from product 1 by simple crystallization to an acceptable level under the ICH guideline. Anisaldehyde was removed from the organic extract as a bisulfite adduct by washing with aqueous Na2S205 twice, prior to the crystallization of 1. Secondly,... 

A particularly useful application of MW-assisted synthesis at elevated pressure has been in the preparation of radiopharmaceuticals containing isotopes with short half-lives, such as C-ll (half-life 20 min) and F-18 (half-life 110 min) [25-27]. Clearly, these compounds have to be synthesized very rapidly in order to give products with high radiochemical yield. For example, [1-11C] tyrosine 12 was synthesized using the two step Bucher-Strecker method by the reaction of p-hydroxyphenylacetaldehyde bisulfite adduct 11 with K11CN and (NH4)2C03 followed by hydrolysis with aqueous NaOH (Scheme 4.7)... 

RCOOH - RCHO (12,485). This borane (2 equiv.) reduces acids at room temperature to thexylboronic acid and aldehydes, which are best isolated as the sodium bisulfite adduct. Yields of aliphatic aldehydes are in the range 80-95%. Reduction of aromatic acids is slow, and yields are significantly lower. 

Synthesis from Citronellal. One of the oldest routes to hydroxydihydrocitronellal is the hydration of the citronellal bisulfite adduct (obtained at low temperature) with sulfuric acid, followed by decomposition with sodium carbonate. A more recent development is hydration of citronellal enamines or imines, followed by hydrolysis [67]. 

Glucose does not form a bisulfite adduct or give a magenta color with the Schiff reagent. 

R = Ph) is the most widely investigated of these compounds and serves as a suitable reference compound. Kalb and Bayer3 reported the methanol, ammonia, aniline, and sodium bisulfite adducts of this compound. The reactivity of the indolone increases when the electron density at the 2-position is reduced. In these cases (158 R = 4-nitrophenyl, 2-pyridyl, C02alkyl),49,61,62,91 the indolone adducts (175 Nu = OH, OEt) are stable and isolable the free indolones do not exist. The 2-alkylindolones (158 R = alkyl), in which the conjugation of the azomethine group is less extensive, are also very reactive. They too are only isolated as adducts (175 R = alkyl Nu = OH) with the exception of 158 (R = 1-Bu, Section IV,A,2). 

Fig. 16 The chemical structure of receptor 87 and the corresponding bisulfite adduct...

DIETHYL ESTER, 33, 23 Cycloheptanone, 34, 19, 24 sodium bisulfite adduct, 34, 25 Cyclohexane, iodo-, 31, 66 A1, -Cyclohexaneacetic acid, a-CYANO-, 31, 25, 26... 

Phenanthrenequinone, 34, 76 sodium bisulfite adduct, 34, 77 p-Phenetidine hydrochloride, 31, 11 Phenol, 34, 44... 

RCH(NH2)COOH - RCHO. Tryptophane is oxidized to indole-3-acetalde-hyde by Chlorox in C6H6 at 50-55°. The crude aldehyde thus obtained (33-60% yield) is purified via a bisulfite adduct. The overall yield of pure product is 60%. Careful control of the pH to > 7.7 is essential since the substrate is unstable to base. 

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