Novel 7-acetylspirobenzofuranone compound of the formula: ##STR1## has gastric secretion inhibitive, antiinflammatory and analgesic activities, and is of value as drugs.

This invention relates to 7-acetylspirobenzofuranone compound and use of 
said compound. 
The present compound is 7-acetylspiro[benzo[b]furan-2(3H), 
1'-cyclopropane]-3-one having the formula (I): 
##STR2## 
The compound (I) of the present invention can be produced, for example, by 
subjecting a compound of the formula(II): 
##STR3## 
wherein R is C.sub.1-4 alkyl, to condensation and decarboxylation in one 
pot with an organic base and a catalyst which assists decarboxylation. 
Referring to the formula (II), examples of the C.sub.1-4 alkyl group R 
include methyl or ethyl. 
In the above reaction, the organic base is employed to promote 
ester-condensation i.e. Dieckmann condensation and the decarboxylating 
catalyst is employed to promote decarboxylation of the condensed compound 
[the formula (III) described hereinafter]. Preferred examples of said 
organic base include tertiary amines (e.g. triethylamine, 
1,4-diazabicyclo[2,2,2]octane or 1,8-diazabicyclo[5,4,0]-7-undecene). 
Preferred examples of said catalyst which assists decarboxylation include 
metal halides (e.g. sodium chloride, sodium bromide, sodium iodide, 
potassium bromide, potassium chloride, potassium iodide, etc.) and 
quaternary ammonium salts (e.g. tetramethylammonium bromide, etc.). The 
reaction temperature is normally about 100.degree. C. to 200.degree. C. 
and preferably about 140.degree. C. to 160.degree. C., although the 
reaction may be conducted at higher or lower temperatures if it is desired 
to control the reaction velocity. Purging the reaction vessel with an 
inert gas (e.g. N.sub.2, argon) is sometimes effective in preventing side 
reactions and improving yields. This reaction is normally carried out in a 
suitable solvent. While any solvent that will not interfere with the 
reaction may be employed, it is normally advantageous to employ a solvent 
having a boiling point higher than the reaction temperature (e.g. dimethyl 
sulfoxide, N,N-dimethylformamide, hexamethylphosphoramide). 
The compound (I) of the present invention can be produced also by 
subjecting a compound of the formula (III): 
##STR4## 
to decarboxylation. 
This reaction is carried out in the presence of the above-mentioned 
decarboxylating catalyst and under similar reaction conditions to those 
described in the condensation and decarboxylation reaction of the compound 
(II) but absence of the organic base which promotes ester condensation. 
The contemplated compound (I) obtained in the foregoing manner can be 
isolated from the reaction mixture and purified by conventional procedures 
(e.g. distillation, recrystallization or column chromatography). 
The spiro compound (I) according to this invention is a new compound which 
exhibits gastric secretion inhibitive, antiinflammatory, analgesic and 
other effects in mammals (e.g. man, rat, mouse, guinea-pig, dog and pig), 
for instance, a intraduodenal administration of 50 mg/kg of the compound 
(I) in rats shows strong suppression of gastric secretion and of ulcer 
formation induced by water-immersion restraint stress, and the compound 
(I) is less toxic. Therefore, it is of value as antiulcer, 
antiinflammatory, analgesic and as drugs for the management of peptic 
ulcer, acute or chronic gastritis, lumbago, arthritis and other diseases. 
Management of a peptic ulcer in accordance with the present invention 
includes both the prophylactic administration of the spiro compound (I) to 
prevent the outbreak of an ulcer in an ulcer prone patient, as well as the 
treatment of an existing peptic ulcer. In such medicinal applications, the 
compound (I) can be safely administered orally or parenterally, either as 
it is or as formulated with pharmaceutically acceptable carriers or 
diluents known per se into suitable dosage forms such as tablets, powders, 
capsules, injections and suppositories. While the recommended dosage 
depends on the subject, condition, route of administration, etc., the 
normal oral dosage for the treatment of peptic ulcer or acute or chronic 
gastritis is about 1 mg. to 20 mg. as compound (I) per kg body weight per 
dose, to be given once to 3 times daily. 
The starting compounds (II) and (III) which are employed in the practice of 
this invention can be prepared by the following route of synthesis or any 
process analogous thereto. 
##STR5## 
wherein R is as defined hereinbefore. 
The carboxy-substituted spiro compound in Reference Example 2 described 
hereinafter can be produced by subjecting the present compound (I) to 
oxidation and said compound including its pharmaceutically acceptable 
salts (e.g. sodium or potassium salt) has the same utility as that of the 
present compound (I). 
The following reference and working examples are intended to describe this 
invention in further detail but should not be considered as limiting the 
scope of this invention in any way. 
REFERENCE EXAMPLE 1 
To a mixture of methyl 3-acetylsalicylate (5.8 g) and potassium carbonate 
(10.4 g) in acetone (200 ml) was added .alpha.-bromo-.gamma.-butyrolactone 
(12.5 g) under stirring, and the mixture was refluxed for 11 hours. The 
insolubles were filtered off and the filtrate was concentrated under 
reduced pressure. The residue was subjected to chromatography on silica 
gel eluting with chloroform. By the above procedure, there was obtained 
.alpha.-[(6-acetyl-2-methoxycarbonylphenyl)oxy]-.gamma.-butyrolactone as 
pale yellow oil. 
Infra red absorption spectrum (IR) .nu..sub.max.sup.film cm.sup.-1 : 1780 
(.gamma.-lactone), 1720 (COOCH.sub.3), 1690 (COCH.sub.3) 
Elemental analysis, for C.sub.14 H.sub.14 O.sub.6 : Calcd.: C, 60.43; H, 
5.07: Found: C, 60.21; H, 5.02.