Preparation of 3-hydroxybutanal
200 ml of ice-cold water are placed in the apparatus which is immersed in a cooling bath.
100 g of freshly distilled acetaldehyde, in portions at a time, are introduced while the cork is momentarily withdrawn, the bottle being agitated slightly during the addition, and great care being taken that the temperature of the contents does not rise above 0° C. A suitable cooling bath for this stage consists of ice, water and a little hydrochloric acid. When all the aldehyde is added, the cooling bath is replaced by one of ice and hydrochloric acid, and when the temperature of the contents of the bottle has fallen to -12° C, 100 ml of a 2-5% solution of potassium cyanide are slowly dropped in while the bottle is rotated; the temperature must be kept below -8° C. After the potassium cyanide is added, the mixture is kept for 2 hours below -8° C, the freezing mixture being renewed if necessary, and then for 30 hours in an ice chest at 0° C. The resulting syrupy solution of pale yellow colour is saturated in the cold with common salt, and then quickly extracted four times with a moderately large volume of ether. The ethereal extracts are dried over anhydrous sodium sulphate, the ether distilled off, and the residue distilled under reduced pressure. Aldol passes over at 80-90° C and 20 mmHg pressure. A suction flask containing conc. sulphuric acid should be placed between the receiver and the pump to absorb aldehyde vapours, which would otherwise prevent a high vacuum being obtained. The yield of 3-hydroxybutanal is 50% theoretical. Colourless, odourless liquid; d=1.12 g/ml at 4° C; b.p. 75° C/10mmHg. On distilling at atmospheric pressure forms acetaldehyde and much crotonaldehyde.
Systematic organic chemistry, by W. M. Cumming, 103-104, 1937.
3-Hydroxybutanal, Aldol, Butanal, 3-hydroxy-, Oxybutanal, 3-Hydroxybutyraldehyde, ACETALDOL, 3-Butanolal, Oxybutyric aldehyde, Butyraldehyde, 3-hydroxy-, beta-Hydroxybutyraldehyde, 107-89-1, NSC 7610, .beta.-Hydroxybutyraldehyde, Butanal, 3-hydroxy-, (S)-, HSDB 2663, HSJKGGMUJITCBW-UHFFFAOYSA-N, EINECS 203-530-2, UN2839, BRN 1735845, AI3-18874, ACMC-20mndn, 3-Hydroxy-butyraldehyde, AC1L1PSX, AC1Q2BUX, WLN: VH1YQ1, Aldol [UN2839] [Poison], CTK6A6898, Aldol [UN2839] [Poison], NSC7610, 117706-98-6, NSC-7610, 7261AF, AKOS006228052, UN 2839, AN-22491, KB-47178, LP083108, LS-47551, OR014571, OR199521, OR207083, DB-008312, FT-0631603, 18764-EP2275105A1, 18764-EP2279741A2, 18764-EP2280007A1, 18764-EP2286915A2, 18764-EP2287157A1, 18764-EP2289868A1, 18764-EP2298753A1, 18764-EP2305684A1, 18764-EP2305808A1, 18764-EP2305825A1, 18764-EP2308847A1, 18764-EP2314576A1, 3B3-063418, 115827-11-7
C4H8O2, CID7897, 4-01-00-03984 (Beilstein Handbook Reference)