5-Hydroxyindoleacetic Acid → 5-Hydroxytryptophol

Temperature

-78 °C

5-Hydroxyindol-3-acetic acid (1.91 g, 10 mmoles) was initially introduced into MC (40 ml) under argon, the mixture was cooled to −78° C. and diisopropylaluminium hydride (0.2 M in toluene, 40 ml, 48 mmoles) was added in the course of 20 min, while stirring. When the addition of the reducing agent had ended, the mixture was allowed to come to RT in the course of 5 hours and was then left at RT for a further hour. For working up, methanol (2 ml) was cautiously added to the reaction mixture. The previously continuously solid mass became liquid again during the addition. Saturated NaCl solution (10 ml) was now added in portions to the mixture. The resulting mixture was left to stand overnight and then filtered off with suction over kieselguhr. The filter cake was washed with a total of 400 ml MC. The filtrate was dried over sodium sulfate and concentrated. 730 mg 3-(2-hydroxy-ethyl)-1H-indol-5-ol were obtained (m.p. 98-102° C.).

1. additionWhen the addition of the reducing agent
2. customto come to RT in the course of 5 hours
3. waitwas then left at RT for a further hour
4. additionagain during the addition
5. waitThe resulting mixture was left
6. filtrationfiltered off with suction over kieselguhr
7. washThe filter cake was washed with a total of 400 ml MC
8. dry with materialThe filtrate was dried over sodium sulfate
9. concentrationconcentrated

ORD record

ord-f9b5e09fc31d4cf2aad2cc3b327f2856

Source dataset

uspto-grants-2011_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07951948B2