Half acid salts

These half acid salts can be named in two ways. The systematic way is to simply name both components HC03 is formed from a hydrogen ion plus a carbonate ion, and is, therefore, named hydrogencarbonate. The common, if less systematic, approach is to call this the bicarbonate ion. 

Dry air is blown through the solution to remove the excess of ammonia, and the solution is then dissolved in its own volume of absolute alcohol. A sample of this solution is titrated with standard oxalic acid, litmus being used as an outside indicator (Note 3). The amount of oxalic acid (Note 4) necessary to form the acid salt is placed in a large evaporating dish and dissolved in 4 1. of 95 per cent alcohol. The amine solution is then slowly run into the acid with constant stirring. During the addition of the last half of the amine solution, the container must be cooled in order to avoid the formation of the neutral oxalate,... 

The amount of malic acid theoretically is sufficient to convert half of the amine to the acid salt and the remaining half to the neutral salt. 

The first successful attempt in asymmetric synthesis was made by Marckwald in 1904 who prepared an active (-) -valeric acid by heating the half brucine salt of ethyl methyl malonic acid at 170°C. 

The preformation of carbazol-9-ylpotassium (sodium) has been much less used for the introduction of acyl groups onto nitrogen examples are the formation of 9-methoxy- and 9-ethoxy-carbonylcarbazoles, the dithio-carbamate salt 51, and the malonate 52 by reaction with the alkoxy-chloroformates, carbon disulhde, and malonic acid half-acid chloride, respectively. 

The point at which, supposedly, 50% of the acid species is transformed in salt corresponds to the half-neutrahzation, i.e., when half the alkahne required to reach the equivalence point has been added. This position corresponds to a buffer zone in which the variation of pH is small with respect to the amoimt of added neutralization solution (Fig. 14 left plot). Hence, in this region a very slight variation of pH can produce a very large variation of neutralization (Fig. 14 right plot), i.e., a considerable alteration of the relative proportion of AH and A . Far away from this pH, the opposite occurs. Consequently, the pH could be used to carry out a formulation scan, but the scale is far from hnear and the variation of pH does not render the variation of the characteristic parameter of the actual surfactant mixture that is at interface [77,78]. The appropriate understanding of the behavior of this kind of acid-salt mixture is particularly important in enhanced oil recovery by alkaline flooding [79,80] and emulsification processes that make use of the acids contained in the crude oils [81-83]. 

Keywords alcoholate, CO2, large scale, carboxylation, gas-solid reaction, carbonic acid half ester salts... 

Optically pure (+)-l-octyn-3-ol may be obtained by recrystallization of the half acid phthalate with (+)-a-methylbenzyl amine (Aldrich Chemical Company). The half acid phthalate salt Is made by heating equal molar amounts of l-ocytn-3-ol and phthalic anhydride. This half acid phthalate derivative... 

In 1972 Link and Bernauer (69) published a synthesis of (+)-isopilosine and of (+)-pilocarpine, and then obtained (—)-epiisopilosine as a by-product. The readily available ester 53 was converted in two steps to the aldehyde (54), which on Stobbe condensation with succinic ester gave the half-ester acid salt 55. Lithium borohydride reduction followed by prolonged acid treatment gave ( )-pilosinine [( )-32], together with 2,3-dehydropilosin-... 

In an older nomenclature system, the word acid was used to denote an acid salt. In another old system, the prefix bi- was used for a half-neutralized acid that originally contained two ionizable hydrogen atoms. Thns, sodium bicarbonate and sodium acid carbonate are other names that have been nsed for NaHC03. 

---