On Sulphonfluoresceïn and some of its Derivatives 5

On Sulphonfluoresceïn and some of its Derivatives 5

[Transcriber’s Note:

The following table was crossed out on the original.

A note on the previous page beside the table was:

 

All these calculations are wrong.

J.R.]

 

I ·1078 gr salt gave ·0304 gr BaSO_{4} = 15·73% Ba.

II ·1641 ” ” ” ·0457 ” ” = 15·53” ”

III ·2425 ” ” ” ·0680 ” ” = 15·65” ”

IV ·2860 ” ” ” ·0798 ” ” = 15·54” ”

V ·1843 ” ” ” ·0498 ” ” = 15·08” ”

VI ·2620 ” ” ” ·0708 ” ” = 15·08” ”

VII ·3230 ” ” ” ·0906 ” ” = 15·65” ”

VIII ·2875 ” ” ” ·0807 ” ” = 15·66” ”

 

Calculated for C_{19}H_{13}O_{7}SBa = 15·10% Ba.

 

In the above determinations the salt analysed was taken from

specimens made at three different times and purified in slightly

different ways, Nos 1, 2, & 3 being washed with absolute alcohol. Nos

V and V were made by precipitating the Ba with H_{2}SO_{4} from a

solution of the salt.

 

The water was determined by heating at 110° till constant weight was

reached. Part only of the weight lost was regained on standing in the

air.

 

·3943 gr salt lost at 110° ·0286 gr = 7.25%

 

Water calculated for C_{19}H_{13}O_{7}SBa+2H_{2}O = 7.35%

 

Although these analyses show a per cent. of Ba somewhat above that

required by a compound having the formula C_{19}H_{13}O_{7}SBa still

this appears to be the most probable formula which can be assigned to

the substance. If this is the true composition of the salt, then in

sulphonfluoresceïn the anhydride condition must be broken up by

boiling with BaCO_{3} forming the salt thus.

 

┌── ──┐ ┌── ──┐

│ │ │ │

│ ┌─ OH │ │ ┌─ OH │

│ │ / │ │ │ / │

│ │ C_{6}H_{3} │ │ │ C_{6}H_{3} │

│ │ \ │ │ │ \ │

│ │ O │ │ │ O │

│ │ / │ │ │ / │

│ C ┤ C_{6}H_{3} │ │ │ C_{6}H_{3} │

│ │ \ │ + H_{2}O = │ C ┤ \ │

│ │ OH │ │ │ OH │

│ │ │ │ │ │

│ │ C_{6}H_{4}SO_{2} │ │ │ C_{6}H_{4}SO_{2}OH │

│ │ / │ │ │ │

│ └─ O │ │ └─ OH │

│ │ │ │

└── ──┘ └── ──┘

 

┌── ──┐ ┌── ──┐

│ │ │ │

│ ┌ OH │ │ ┌ OH │

│ │ / │ │ │ / │

│ │ C_{6}H_{3} │ │ │ C_{6}H_{3} │

│ │ \ │ │ │ \ │

│ │ O │ │ │ O │

│ │ / │ │ │ / │

│ │ C_{6}H_{3} │ │ │ C_{6}H_{3} │

2 │ C ┤ \ │ + BaCO_{3} = │ C ┤ \ │ Ba.

│ │ OH │ │ │ OH │

│ │ │ │ │ │

│ │C_{6}H_{4}SO_{2}OH │ │ │ C_{6}H_{4}SO_{2}O │

│ │ │ │ │ │

│ └ OH │ │ └ OH │

│ │ │ │

└── ──┘ └── ──┘_{2}

 

By treating the salt with H_{2}SO_{4} the original

substance is reformed.

 

 

Calcium Salt.

 

Attempts were made to prepare the calcium salt but without success.

The S-fluoresceïn was boiled several hours with very finely powdered

calcite, and some salt was formed as shown by the CO_{2} evolved

but on evaporating the solution and recrystallizing the substance

deposited it was found to be the unchanged S-fluoresceïn. Some Ca.

salt was in the mother liquors but its extreme solubility prevented a

separation being made.

 

 

Acetyl derivative of S.fluoresceïn.

 

S.fluoresceïn was boiled with an excess of acetic anhydride for about

three hours. The solution became quite dark and when evaporated on

the water bath left a black tarry residue. This was treated with

water which dissolved a part leaving a dark flocculent precipitate.

The solution was boiled with animal charcoal and evaporated nearly

to dryness. On cooling there separated a light yellow flocculent

precipitate very soluble in hot water and but slightly less so in

cold. This was dissolved in a small quantity of alcohol from which

it separated on evaporation in small radial crystals having a light

lavender color & satiny luster. They also have a peculiar odor

resembling slippery elm which is not removed by recrystallization.

They show a tendency to decompose, becoming yellow on exposure to

the air. The substance does not melt or change in appearance under

245°. With alkalis it gives a slight greenish fluorescence. From the

method of its formation this was taken to be an acetyl derivative

of S.fluoresceïn but whether the mono-or di-acetyl could not be

determined without analysis for which the substance did not suffice.

 

 

Bromine substitution products of S-fluoresceïn.

 

It was especially interesting to see what influence the SO_{2} group

would exert upon the introduction of Bromine into the compound. In

the case of fluoresceïn four Bromine atoms enter easily and special

precautions are necessary to obtain a product containing a smaller

number. The case however is different with S.fluoresceïn.

 

The latter was dissolved in glacial acetic acid in which it is

soluble with some difficulty and to the solution was added a 20%

solution of bromine in acetic acid, in sufficient quantity to make

eight atoms of bromine to one molecule of S.fluoresceïn. This

solution was evaporated on the water bath and while still having a

considerable volume, small, red, sharply defined crystals began to

separate. The solution was evaporated to a small volume and allowed

to cool but nothing further separated. These crystals are difficultly

soluble in water, alcohol and ether. The alkaline solution shows a

green fluorescence and slight red color by transmitted light. These

crystals were dissolved in a large quantity of alcohol which on

evaporation gradually deposited very small yellow crystals, which

were dried in the air and taken for analysis. The Br. was determined

by Carius method.

 

I. ·2345 gr sub. gave ·1718 gr AgBr = 31·17% Br.

II. ·2786 gr ” ” ·1815 gr ” = 27·72% Br.

 

Calculated for C_{19}H_{10}Br_{2}O_{6}S = 30·42% Br.

 

These results, though not conclusive, indicate that under the

given conditions it is the di-bromsulphonfluoresceïn which is

formed. Whether this is due to the presence in the compound of the

SO_{2} group or simply to the greater insolubility of the di-than

of the tetra-brom product cannot be definitely stated. When the

original acetic acid mother liquor was evaporated to dryness, a red

non-crystalline substance remained which more closely resembled rosin

than the crystals. The concentrated alkaline solution had a deep red

color without fluorescence and acted as a red dye stuff. The dilute

alkaline solution showed the characteristic delicate pink of rosin.

 

 

Action of H_{2}SO_{4} on S.fluoresceïn.

 

A test tube in which S.fluoresceïn was being made just at the end

of the reaction broke and allowed the contents to run out into the

sulphuric acid bath, which had a temperature of 175°. On standing

several days the solution deposited a heavy precipitate which was

separated by filtering through glass wool. When dry it formed a light

yellow powder extremely soluble in water, alcohol and ether.

 

The alkaline solution had an intense green fluorescence with

delicate shades of pink by transmitted light. On account of its

great solubility it was impossible to purify it by crystallization,

hence the Ba salt was made. The substance decomposed BaCO_{3} with

great ease forming an easily soluble salt. When it was attempted to

evaporate the solution of this salt to crystallization the latter

came out in a hard insoluble granular form and on continuous boiling

of the solution turned brown. To avoid this undesirable form it was

converted into the Ca. salt by treatment with H_{2}SO_{4} and then

CaCO_{3}. This also formed a hard granular insoluble mass on boiling

but did not change in color. As there was no guarantee as to its

purity and only a small quantity was obtained it was not analyzed.

 

 

Action of HCl on S.fluoresceïn.

 

Hydrochloric acid does not dissolve S.fluoresceïn but converts it

into a light yellow granular powder. When recrystallized from water

in which it is quite easily soluble it melts partially at 130°

apparently with some decomposition. This compound was not further studied.