Xylenolblue (p-Xylenol Blue) is an acid-base indicator used as an intermediate in chemical synthesis.

1. Application of acid-base indicators
pH range:
Below pH 8.0, the solution is yellow.
In the pH range of 8.0 to 9.6, the color transitions to purple-red.
Above pH 9.6, the solution is blue.
How to use:
1. Prepare Xylenol Blue indicator solution (common concentration is 0.04% to 0.1% w/v, dissolved in ethanol or water).
2. Add the indicator solution to the sample to be tested (recommended dosage is 1-2 drops per 10 mL sample).
3. Observe the color change and determine the pH value by comparing the color with the standard pH colorimetric card.
2. Application in chemical synthesis
How to use:
1. Add Xylenol Blue to the synthesis system according to the needs of the target reaction, and control the concentration and reaction conditions.
2. Under appropriate conditions (such as light, heat or catalyst), induce chemical reactions to produce target products.

The above information is based on published literature. Experimental procedures should be appropriately modified to meet specific research demands.