Dimethyl Sulfoxide → Benzothiazole

HRID 380185Notes

Reaction equation

HRID 380185 reaction equation
[CH2:1](C1(CC)C2C=C(C=O)C=CC=2C2C1=CC(Br)=CC=2)C.[NH2:21][C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][C:23]=1[SH:28].CS(C)=O>O>[S:28]1[C:23]2[CH:24]=[CH:25][CH:26]=[CH:27][C:22]=2[N:21]=[CH:1]1

Participants

5

Reactant 3

HCID 679Dimethyl SulfoxideHCID 87132-AminothiophenolHCID 154763497-Bromo-9,9-diethylfluorene-2-carboxaldehyde

Product 1

HCID 7222BenzothiazoleYield 80.3%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
195 °C

Procedure

A mixture of 9,9-Diethyl-7-bromo-fluorene-2-carboxaldehyde (49.35 g., 0.15 mol.), 2-amino thiophenol (20 ml. 0.187 mol., 1,25 eq.), and DMSO (110 ml) was heated in an oil bath to a bath temperature of 195° C., held there for 45 minutes, and then poured into water. The separated solids were collected, reslurried in 1:4 acetic acid-water (1000 ml.) filtered, and washed with water and dilute sodium bicarbonate solution. These solids, 80.05 g., were then reslurried in hot ethanol, (600 ml), cooled and filtered to get the product benzothiazole, 45.69 g., m.p. 133.6-135° C. An additional 6.6 g., m.p. 134.6-135.5° C., was obtained by chromatography of the ethanol filtrate. Total recovery 52.29 g. (80.3% yield). Mass Spec: m/z 433, 435, (M+). Anal: Calcd for C24H20BrNS: C, 66.37; H, 4.64; Br, 18.40; N, 3.23; and S, 7.37. Found: C, 66.46; H, 4.52; Br, 18.54; N, 3.14; and S, 7.19.

Workup

  1. customThe separated solids were collected
  2. filtrationfiltered
  3. washwashed with water and dilute sodium bicarbonate solution
  4. temperaturecooled
  5. filtrationfiltered

Sources & evidence

ORD record
ord-aecd38f1d0544978a4a98f36cc9ee1f2
Source dataset
uspto-grants-2001_10
Patent number
US06300502B1

Reaction notes

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