Hydroxy compounds, with

A fairly general procedure consists in coupling a phenol or naphthol with a diazotised amine, reducing the product to an aminophenol or aminonaphthol, and oxidising the hydroxy compound with acid ferric chloride solution. This method is illustrated by the preparation of (3 (or 1 2)-naphthoquinone ... 

Hydroxyhc Compounds. Chloioformates on reaction with water give the patent hydroxy compound, HCl, and CO2 as weU as the symmetrical carbonate formed by the reaction of the hydroxy compound with chloroformate. 

Amino groups are acetylated normally and are converted to hydroxy compounds with nitrous acid. Tlie 2,3-diamino [2,3-f>] derivative gives an imidazolo fused pyridopyrazine with acetic anhydride (75USP3898216). The oxidative removal of hydrazino groups has been used to give ring-unsubstituted derivatives (79JHC305). 

Methyl-4-hydroxyquinazoline reacts with organic halides, in the presence of sodium methoxide, to give 3-substituted 2-methyl-4(3i/)-quinazolinones. The 0-acetyl derivative of 4-hydroxyquinazoline has been prepared under anhydrous conditions and gives the hydroxy compound with water or with lithium aluminum hydride. The N-3 acetyl derivative, however, is more stable and gives 3-methyl-4(31/)-quinazolinone with lithium aluminum hydride. ... 

E. Potential Hydroxy Compounds with a Ring System Containing Three or Four Hetero Atoms. ... 

An example of a completely stereoselective cyclization of an allylsilane, leading to a seven-mem-bered ring in excellent yield, is known158. Treatment of the hydroxy compound with methanesulfonyl chloride and triethylamine in acetonitrile gives a single isomer of the bicyclic compound via cyclization of the (T )-iminium ion. 

As explained in Chapter 1, the urethane group is the product of the reaction of a hydroxy compound with an isocyanate group (Reaction 4.8). This reaction occurs by step kinetics, yet is usually an addition process since no small molecule is lost as the reaction proceeds. 

Several examples of the dehydration of acyclic and cyclic hydroxy compounds with CDI, AfN -thiocarbonyldiimidazole, and A -sulfmyldiimidazole, are shown below. 

Reactions of trident and ambident anions of hydroxy compounds with alkylating reagents were also studied.121 The ion-pair extraction method was found to be superior alkylating agents were methyl iodide (soft) and dimethyl sulfate (hard). Upon alkylation by ion-pair extraction the 5-methyl-substituted selenolene-2-one system gives mainly C-alkylation with the soft acid, methyl iodide, and mainly O-alkylation with the hard acid, dimethyl sulfate. 

FIGURE 7.12 Preparation of activated esters of A-alkoxycarbonylamino acids by reaction of the hydroxy compound with a mixed anhydride (path A), obtained by leaving the three reagents (NMM = A-methylmorpholine) in CH2C12 at 23°C for 2 minutes.35 Mixed carbonate that is formed (path B) is readily eliminated by crystallization of the ester. 

Polyurethanes are macromolecules in which the constitutional repeating units (CRUs) are coupled with one another through urethane (oxycarbonylamino) groups. They are prepared almost exclusively by stepwise addition polymerization reactions of di- or polyfunctional hydroxy compounds with di- or polyfunctional isocyanates ... 

Epoxy resins are usually understood to be products of reaction of polyfunctional hydroxy compounds with l-chloro-2,3-epoxypropane (epichlorohydrin) in basic medium. In the simplest case two mol of epichlorohydrin react, for example, with one mol of bisphenol A, according to the following scheme ... 

Moreover, flexible foams are characterized by utilization of special emulsifiers in their synthesis yielding an open-cell architecture, whereas for rigid foams emulsifiers are chosen that create more closed-cell structures. As diisocyanate for both types, the commercially available mixture of 80% 2,4-toluene diisocyanate and 20% 2,6-toluene diisocyanate is especially suitable. If foam formation is to take place at room temperature, and especially when hydroxy compounds with secondary hydroxy groups are used [poly(propylene glycol)s], the presence of a catalyst is generally required (see Sect. 4.2.1). 

The benzodiazepine (236) can be chlorinated at the 1-position using sodium hypochloride or t-butyl hypochlorite, or at the 3-position using NCS. The 3-chloro derivative can also be prepared by treatment of the 3-hydroxy compound with thionyl chloride. Halogens at the 3-position can be displaced to give 3-amino derivatives. 

In the condensation of diols, halogenated alcohols, amino alcohols, cyclic hydroxy ethers, or other bifunctional hydroxy compounds with carbodiimides, 5-, 6-, and 7-membered 1,3-O-N- or l,3-7V,7V-heterocyclics are obtained [14]. 

Both aromatic and aliphatic fluoroformates 7 can be readily prepared from phenols or alcohols and carbonyl difluoride and treated with sulfur tetrafluoride without isolation. Hydrogen fluoride evolved in the reaction of hydroxy compounds with carbonyl di fluoride serves as a catalyst for the consecutive reaction with sulfur tetrafluoride.15<)-162 This provides a general, convenient, direct synthesis of aryl and alkyl trifluoromethyl ethers 5 from phenols and alcohols. When the intermediate fluoroformate 7 is isolated prior to treatment with sulfur tetrafluoride, at least one mole equivalent of hydrogen fluoride is necessary to promote the fluorination reaction. 159 163 Representative examples of the conversion of hydroxy compounds 6 into trifluoromethyl ethers 5 via intermediate fluoroformates 7 are given (for other examples 7 -> 5, see Houben-Weyl, Vol. E4, pp 628. 629). 

Equilibria between hydroxyphosphoranes and phosphoric esters have been claimed to occur as intermediates170-172, or have been shown to exist by trapping the hydroxy compound with diazomethane as above173, or have been displaced by acido-basic variations174, as with 96 and 97 in Scheme 21. 

Diazotization has been reported for all the pyrazolopyridines, and in some cases the salts have been isolated. A 7-aminopyrazolo[4,3-c]pyridine (191a) was converted to the corresponding hydroxy compound with sodium nitrite in hot glacial acetic acid.159 Analogous products were obtained from a 3-aminopyrazolo[3,4-b]-15 and 2-aminopyrazolo[l,5-a]pyridine.186 Decomposition of diazonium salts with hydrobromic acid afforded 3-bromo-pyrazolo[3,4-c]-u0 or -[4,3-bjpyridines111 deamination of 3-aminopyra-zolo[3,4-h]pyridines was achieved via treatment of the diazonium salts with hypophosphorous acid,10 titanous chloride,238 or ferrous ammonium sulfate.238 Kocevar et al.236 have made a detailed study of the reactions of the latter diazonium salt. 

In in vitro experiments, Lipschitz and Bueding42 found that the liver, and, to a much lesser extent, the kidney were the only tissues of the rabbit, rat and guineapig which could conjugate various hydroxy compounds with D-glucuronic acid. Lewy and Storey43 48 found that mouse liver slices conjugate o-aminophenol with D-glucuronic acid, but that kidney was much less active and spleen inactive. 

The hydrogenation of 2,4-diketo acid derivatives 6-9 to the corresponding 2-hydroxy compounds with cinchona-modified Pt catalysts as depicted in Scheme 18.1 can be carried out with chemoselectivities... 

The classical route to chloropyrazines is by treatment of a hydroxy-pyrazine with phosphoryl chloride bromopyrazines are similarly prepared by using phosphoryl bromide, phosphorus tribromide, or a mixture of both. Thus, treatment of hydro xypyrazine with phosphoryl chloride gives chloropyrazine in 92% yield,147 and treatment of the hydroxy compound with a mixture of phosphoryl bromide and phosphorus tribromide gives bromopyrazine in 58% yield.266 The use of phosphorus pentahalides frequently leads to substitution products (Scheme 22) for example, when hydroxypyrazine is treated with a mixture of phosphoryl bromide and phosphorus pentabromide both monobromo- and 2,6-dibromopyrazines are formed.287,268 Bromina-tion of hydroxypyrazine with bromine in the presence of small... 

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